diff --git a/package.json b/package.json
index 1e0e50551e350b5a397a1a15fd63e16b494f0be5..d82e5d2330b57e46c6a4cde344b9d454853ff858 100644
--- a/package.json
+++ b/package.json
@@ -30,20 +30,16 @@
 		"@fortawesome/fontawesome-free-brands": "5.0.2",
 		"@fortawesome/fontawesome-free-regular": "5.0.2",
 		"@fortawesome/fontawesome-free-solid": "5.0.2",
+		"@koa/cors": "2.2.1",
 		"@prezzemolo/rap": "0.1.2",
 		"@prezzemolo/zip": "0.0.3",
 		"@types/bcryptjs": "2.4.1",
-		"@types/body-parser": "1.16.8",
 		"@types/chai": "4.1.2",
 		"@types/chai-http": "3.0.4",
-		"@types/compression": "0.0.36",
-		"@types/cookie": "0.3.1",
-		"@types/cors": "2.8.3",
 		"@types/debug": "0.0.30",
 		"@types/deep-equal": "1.0.1",
 		"@types/elasticsearch": "5.0.22",
 		"@types/eventemitter3": "2.0.2",
-		"@types/express": "4.11.1",
 		"@types/gm": "1.17.33",
 		"@types/gulp": "3.8.36",
 		"@types/gulp-htmlmin": "1.3.32",
@@ -56,18 +52,24 @@
 		"@types/is-root": "1.0.0",
 		"@types/is-url": "1.2.28",
 		"@types/js-yaml": "3.11.1",
-		"@types/kue": "^0.11.8",
+		"@types/koa": "2.0.45",
+		"@types/koa-bodyparser": "4.2.0",
+		"@types/koa-compress": "^2.0.8",
+		"@types/koa-favicon": "2.0.19",
+		"@types/koa-mount": "3.0.1",
+		"@types/koa-multer": "1.0.0",
+		"@types/koa-router": "7.0.27",
+		"@types/koa-send": "4.1.1",
+		"@types/koa__cors": "2.2.2",
+		"@types/kue": "0.11.8",
 		"@types/license-checker": "15.0.0",
 		"@types/mkdirp": "0.5.2",
 		"@types/mocha": "5.0.0",
 		"@types/mongodb": "3.0.12",
 		"@types/monk": "6.0.0",
-		"@types/morgan": "1.7.35",
 		"@types/ms": "0.7.30",
-		"@types/multer": "1.3.6",
-		"@types/node": "9.6.2",
+		"@types/node": "9.6.4",
 		"@types/nopt": "3.0.29",
-		"@types/proxy-addr": "2.0.0",
 		"@types/pug": "2.0.4",
 		"@types/qrcode": "0.8.1",
 		"@types/ratelimiter": "2.1.28",
@@ -76,7 +78,6 @@
 		"@types/request-promise-native": "1.0.14",
 		"@types/rimraf": "2.0.2",
 		"@types/seedrandom": "2.4.27",
-		"@types/serve-favicon": "2.2.30",
 		"@types/speakeasy": "2.0.2",
 		"@types/tmp": "0.0.33",
 		"@types/uuid": "3.4.3",
@@ -84,27 +85,22 @@
 		"@types/webpack-stream": "3.2.10",
 		"@types/websocket": "0.0.38",
 		"@types/ws": "4.0.2",
-		"accesses": "2.5.0",
 		"animejs": "2.2.0",
 		"autosize": "4.0.1",
 		"autwh": "0.1.0",
 		"bcryptjs": "2.4.3",
-		"body-parser": "1.18.2",
 		"bootstrap-vue": "2.0.0-rc.6",
 		"cafy": "3.2.1",
 		"chai": "4.1.2",
 		"chai-http": "4.0.0",
 		"chalk": "2.3.2",
-		"compression": "1.7.2",
-		"cookie": "0.3.1",
-		"cors": "2.8.4",
 		"crc-32": "1.2.0",
 		"css-loader": "0.28.11",
 		"debug": "3.1.0",
 		"deep-equal": "1.0.1",
 		"deepcopy": "0.6.3",
 		"diskusage": "0.2.4",
-		"dompurify": "^1.0.3",
+		"dompurify": "1.0.3",
 		"elasticsearch": "14.2.2",
 		"element-ui": "2.3.3",
 		"emojilib": "2.2.12",
@@ -113,7 +109,6 @@
 		"eslint-plugin-vue": "4.4.0",
 		"eventemitter3": "3.0.1",
 		"exif-js": "2.3.0",
-		"express": "4.16.3",
 		"file-loader": "1.1.11",
 		"file-type": "7.6.0",
 		"fuckadblock": "3.2.1",
@@ -135,12 +130,20 @@
 		"hard-source-webpack-plugin": "0.6.4",
 		"highlight.js": "9.12.0",
 		"html-minifier": "3.5.14",
-		"http-signature": "^1.2.0",
+		"http-signature": "1.2.0",
 		"inquirer": "5.2.0",
 		"is-root": "2.0.0",
 		"is-url": "1.2.4",
 		"js-yaml": "3.11.0",
 		"jsdom": "11.7.0",
+		"koa": "2.5.0",
+		"koa-bodyparser": "4.2.0",
+		"koa-compress": "^2.0.0",
+		"koa-favicon": "2.0.1",
+		"koa-mount": "3.0.0",
+		"koa-multer": "1.0.2",
+		"koa-router": "7.4.0",
+		"koa-send": "4.1.3",
 		"kue": "0.11.6",
 		"license-checker": "18.0.0",
 		"loader-utils": "1.1.0",
@@ -150,9 +153,7 @@
 		"moji": "0.5.1",
 		"mongodb": "3.0.6",
 		"monk": "6.0.5",
-		"morgan": "1.9.0",
 		"ms": "2.1.1",
-		"multer": "1.3.0",
 		"nan": "2.10.0",
 		"node-sass": "4.8.3",
 		"node-sass-json-importer": "3.1.6",
@@ -163,7 +164,6 @@
 		"os-utils": "0.0.14",
 		"progress-bar-webpack-plugin": "1.11.0",
 		"prominence": "0.2.0",
-		"proxy-addr": "2.0.3",
 		"pug": "2.0.3",
 		"punycode": "2.1.0",
 		"qrcode": "1.2.0",
@@ -178,7 +178,6 @@
 		"s-age": "1.1.2",
 		"sass-loader": "6.0.7",
 		"seedrandom": "2.4.3",
-		"serve-favicon": "2.5.0",
 		"speakeasy": "2.0.0",
 		"style-loader": "0.20.3",
 		"stylus": "0.54.5",
@@ -198,7 +197,6 @@
 		"url-loader": "1.0.1",
 		"uuid": "3.2.1",
 		"v-animate-css": "0.0.2",
-		"vhost": "3.0.2",
 		"vue": "2.5.16",
 		"vue-cropperjs": "2.2.0",
 		"vue-js-modal": "1.3.12",
diff --git a/src/client/app/boot.js b/src/client/app/boot.js
index 0846e4bd55c7be83a4dbc9d32842a5a7259d736f..ef828d963749f84f9e82fa9cabb98d9e9be973dd 100644
--- a/src/client/app/boot.js
+++ b/src/client/app/boot.js
@@ -97,6 +97,8 @@
 
 		// Compare versions
 		if (meta.version != ver) {
+			localStorage.setItem('v', meta.version);
+
 			alert(
 				'Misskeyの新しいバージョンがあります。ページを再度読み込みします。' +
 				'\n\n' +
diff --git a/src/client/app/common/mios.ts b/src/client/app/common/mios.ts
index 5e0c7d2f3b511d912a7cce68e7bc1332a39cb04f..ccc73eebc33712329ebdb4fb8d6612d2fc425fd9 100644
--- a/src/client/app/common/mios.ts
+++ b/src/client/app/common/mios.ts
@@ -444,14 +444,17 @@ export default class MiOS extends EventEmitter {
 		// Append a credential
 		if (this.isSignedIn) (data as any).i = this.i.token;
 
-		const viaStream = localStorage.getItem('enableExperimental') == 'true';
-
 		return new Promise((resolve, reject) => {
+			const viaStream = this.stream.hasConnection &&
+				(localStorage.getItem('apiViaStream') ? localStorage.getItem('apiViaStream') == 'true' : true);
+
 			if (viaStream) {
 				const stream = this.stream.borrow();
 				const id = Math.random().toString();
 
 				stream.once(`api-res:${id}`, res => {
+					if (--pending === 0) spinner.parentNode.removeChild(spinner);
+
 					if (res.res) {
 						resolve(res.res);
 					} else {
@@ -503,7 +506,7 @@ export default class MiOS extends EventEmitter {
 						reject(body.error);
 					}
 				}).catch(reject);
-			/*}*/
+			}
 		});
 	}
 
diff --git a/src/client/app/common/views/components/messaging-room.vue b/src/client/app/common/views/components/messaging-room.vue
index d30c64d74a99f4a1c50ca06655d3cad797c12a12..e1b775c33a391abb27853fb0ddd8cced0d0ce47b 100644
--- a/src/client/app/common/views/components/messaging-room.vue
+++ b/src/client/app/common/views/components/messaging-room.vue
@@ -151,7 +151,7 @@ export default Vue.extend({
 			// サウンドを再生する
 			if ((this as any).os.isEnableSounds) {
 				const sound = new Audio(`${url}/assets/message.mp3`);
-				sound.volume = localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) / 100 : 1;
+				sound.volume = localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) / 100 : 0.5;
 				sound.play();
 			}
 
diff --git a/src/client/app/common/views/components/othello.game.vue b/src/client/app/common/views/components/othello.game.vue
index b9d946de96c30f776c6cb25ecb48e67ce8a34ca3..8c646cce07402e7a55c3fd39bc9216f2cabf4d5d 100644
--- a/src/client/app/common/views/components/othello.game.vue
+++ b/src/client/app/common/views/components/othello.game.vue
@@ -164,7 +164,7 @@ export default Vue.extend({
 			// サウンドを再生する
 			if ((this as any).os.isEnableSounds) {
 				const sound = new Audio(`${url}/assets/othello-put-me.mp3`);
-				sound.volume = localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) / 100 : 1;
+				sound.volume = localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) / 100 : 0.5;
 				sound.play();
 			}
 
@@ -188,7 +188,7 @@ export default Vue.extend({
 			// サウンドを再生する
 			if ((this as any).os.isEnableSounds && x.color != this.myColor) {
 				const sound = new Audio(`${url}/assets/othello-put-you.mp3`);
-				sound.volume = localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) / 100 : 1;
+				sound.volume = localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) / 100 : 0.5;
 				sound.play();
 			}
 		},
diff --git a/src/client/app/common/views/components/signup.vue b/src/client/app/common/views/components/signup.vue
index 30fe7b7ad025d0525bd2d83ccbae15357ea1d592..40262b54d31adc6d96278885af750bb978ed3470 100644
--- a/src/client/app/common/views/components/signup.vue
+++ b/src/client/app/common/views/components/signup.vue
@@ -77,7 +77,7 @@ export default Vue.extend({
 
 			const err =
 				!this.username.match(/^[a-zA-Z0-9_]+$/) ? 'invalid-format' :
-				this.username.length < 3 ? 'min-range' :
+				this.username.length < 1 ? 'min-range' :
 				this.username.length > 20 ? 'max-range' :
 				null;
 
diff --git a/src/client/app/common/views/components/url-preview.vue b/src/client/app/common/views/components/url-preview.vue
index e91e510550e7ddb041d19e28095c558bc2b6f4c1..fd25480f612489a48c7fc2c6e6b9fb529fc4b7cb 100644
--- a/src/client/app/common/views/components/url-preview.vue
+++ b/src/client/app/common/views/components/url-preview.vue
@@ -45,7 +45,7 @@ export default Vue.extend({
 		} else if (url.hostname == 'youtu.be') {
 			this.youtubeId = url.pathname;
 		} else {
-			fetch('/api:url?url=' + this.url).then(res => {
+			fetch('/url?url=' + this.url).then(res => {
 				res.json().then(info => {
 					this.title = info.title;
 					this.description = info.description;
diff --git a/src/client/app/desktop/views/components/settings.vue b/src/client/app/desktop/views/components/settings.vue
index 4184ae82c7c36d106561bcd4dde9199f04b97b97..9d074165e50fc89f04de6233d941318b6ee7920b 100644
--- a/src/client/app/desktop/views/components/settings.vue
+++ b/src/client/app/desktop/views/components/settings.vue
@@ -26,6 +26,12 @@
 			<mk-switch v-model="autoPopout" text="ウィンドウの自動ポップアウト">
 				<span>ウィンドウが開かれるとき、ポップアウト(ブラウザ外に切り離す)可能なら自動でポップアウトします。この設定はブラウザに記憶されます。</span>
 			</mk-switch>
+			<details>
+				<summary>詳細設定</summary>
+				<mk-switch v-model="apiViaStream" text="ストリームを経由したAPIリクエスト">
+					<span>この設定をオンにすると、websocket接続を経由してAPIリクエストが行われます(パフォーマンス向上が期待できます)。オフにすると、ネイティブの fetch APIが利用されます。この設定はこのデバイスのみ有効です。</span>
+				</mk-switch>
+			</details>
 		</section>
 
 		<section class="web" v-show="page == 'web'">
@@ -223,7 +229,8 @@ export default Vue.extend({
 			checkingForUpdate: false,
 			enableSounds: localStorage.getItem('enableSounds') == 'true',
 			autoPopout: localStorage.getItem('autoPopout') == 'true',
-			soundVolume: localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) : 100,
+			apiViaStream: localStorage.getItem('apiViaStream') ? localStorage.getItem('apiViaStream') == 'true' : true,
+			soundVolume: localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) : 50,
 			lang: localStorage.getItem('lang') || '',
 			preventUpdate: localStorage.getItem('preventUpdate') == 'true',
 			debug: localStorage.getItem('debug') == 'true',
@@ -240,6 +247,9 @@ export default Vue.extend({
 		autoPopout() {
 			localStorage.setItem('autoPopout', this.autoPopout ? 'true' : 'false');
 		},
+		apiViaStream() {
+			localStorage.setItem('apiViaStream', this.apiViaStream ? 'true' : 'false');
+		},
 		enableSounds() {
 			localStorage.setItem('enableSounds', this.enableSounds ? 'true' : 'false');
 		},
@@ -337,7 +347,7 @@ export default Vue.extend({
 		},
 		soundTest() {
 			const sound = new Audio(`${url}/assets/message.mp3`);
-			sound.volume = localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) / 100 : 1;
+			sound.volume = localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) / 100 : 0.5;
 			sound.play();
 		}
 	}
diff --git a/src/client/app/desktop/views/components/timeline.vue b/src/client/app/desktop/views/components/timeline.vue
index e1f88b62f3d7f1e392500ff4943b93be4e604529..f148e840ad53b78daefe32a5fe3a29f75c61d71b 100644
--- a/src/client/app/desktop/views/components/timeline.vue
+++ b/src/client/app/desktop/views/components/timeline.vue
@@ -97,7 +97,7 @@ export default Vue.extend({
 			// サウンドを再生する
 			if ((this as any).os.isEnableSounds) {
 				const sound = new Audio(`${url}/assets/post.mp3`);
-				sound.volume = localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) / 100 : 1;
+				sound.volume = localStorage.getItem('soundVolume') ? parseInt(localStorage.getItem('soundVolume'), 10) / 100 : 0.5;
 				sound.play();
 			}
 
diff --git a/src/client/app/desktop/views/components/ui.header.account.vue b/src/client/app/desktop/views/components/ui.header.account.vue
index ec4635f338e56c8ac2f68022ae9e9138993fde45..61c30192946941598813374550dbdc26474411af 100644
--- a/src/client/app/desktop/views/components/ui.header.account.vue
+++ b/src/client/app/desktop/views/components/ui.header.account.vue
@@ -18,6 +18,9 @@
 				</li>
 			</ul>
 			<ul>
+				<li>
+					<a href="/i/customize-home">%fa:wrench%カスタマイズ%fa:angle-right%</a>
+				</li>
 				<li @click="settings">
 					<p>%fa:cog%%i18n:desktop.tags.mk-ui-header-account.settings%%fa:angle-right%</p>
 				</li>
diff --git a/src/client/assets/404.js b/src/client/assets/404.js
deleted file mode 100644
index 9e498fe7c2868727a5388fd6d13bfe4c5b4d2902..0000000000000000000000000000000000000000
--- a/src/client/assets/404.js
+++ /dev/null
@@ -1,25 +0,0 @@
-const yn = window.confirm(
-	'サーバー上に存在しないスクリプトがリクエストされました。お使いのMisskeyのバージョンが古いことが原因の可能性があります。Misskeyを更新しますか？\n\nA script that does not exist on the server was requested. It may be caused by an old version of Misskey you’re using. Do you want to delete the cache?');
-
-const langYn = window.confirm('また、言語を日本語に設定すると解決する場合があります。日本語に設定しますか？\n\nAlso, setting the language to Japanese may solve the problem. Would you like to set it to Japanese?');
-
-if (langYn) {
-	localStorage.setItem('lang', 'ja');
-}
-
-if (yn) {
-	// Clear cache (serive worker)
-	try {
-		navigator.serviceWorker.controller.postMessage('clear');
-
-		navigator.serviceWorker.getRegistrations().then(registrations => {
-			registrations.forEach(registration => registration.unregister());
-		});
-	} catch (e) {
-		console.error(e);
-	}
-
-	localStorage.removeItem('v');
-
-	location.reload(true);
-}
diff --git a/src/client/docs/layout.pug b/src/client/docs/layout.pug
index 29d2a3ff69b0e1fad304629d9f14b6f228d65efc..1d9ebcb4cd094805cf23cc493f82c7d5d0e27815 100644
--- a/src/client/docs/layout.pug
+++ b/src/client/docs/layout.pug
@@ -6,7 +6,7 @@ html(lang= lang)
 		meta(name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no")
 		title
 			| #{title} | Misskey Docs
-		link(rel="stylesheet" href="/assets/style.css")
+		link(rel="stylesheet" href="/docs/assets/style.css")
 		block meta
 
 		//- FontAwesome style
diff --git a/src/config/types.ts b/src/config/types.ts
index f802e70d1e0e24e1fb4a4f27eda154612c293799..b181f2c8c1529eaf9090a881d7211014fb57b0ba 100644
--- a/src/config/types.ts
+++ b/src/config/types.ts
@@ -41,10 +41,6 @@ export type Source = {
 		secret_key: string;
 	};
 	accesslog?: string;
-	accesses?: {
-		enable: boolean;
-		port: number;
-	};
 	twitter?: {
 		consumer_key: string;
 		consumer_secret: string;
diff --git a/src/index.ts b/src/index.ts
index 68b289793bd5e0312c66c3db02bfee50cbbf4c11..d633fcbbcba19b23f3182e2529e5a7d65074c014 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -10,7 +10,6 @@ import * as debug from 'debug';
 import chalk from 'chalk';
 // import portUsed = require('tcp-port-used');
 import isRoot = require('is-root');
-import { master } from 'accesses';
 import Xev from 'xev';
 
 import Logger from './utils/logger';
@@ -73,11 +72,6 @@ async function masterMain(opt) {
 
 	Logger.info(chalk.green('Successfully initialized :)'));
 
-	// Init accesses
-	if (config.accesses && config.accesses.enable) {
-		master();
-	}
-
 	spawnWorkers(() => {
 		if (!opt['only-processor']) {
 			Logger.info(chalk.bold.green(
diff --git a/src/models/access-token.ts b/src/models/access-token.ts
index 4451ca140d106ac8e11e6c7c655971ca790c6b9c..9909ea01ad4595544a826061579b722b8ff8b5c9 100644
--- a/src/models/access-token.ts
+++ b/src/models/access-token.ts
@@ -1,12 +1,12 @@
 import * as mongo from 'mongodb';
 import db from '../db/mongodb';
 
-const AccessToken = db.get<IAccessTokens>('accessTokens');
+const AccessToken = db.get<IAccessToken>('accessTokens');
 AccessToken.createIndex('token');
 AccessToken.createIndex('hash');
 export default AccessToken;
 
-export type IAccessTokens = {
+export type IAccessToken = {
 	_id: mongo.ObjectID;
 	createdAt: Date;
 	appId: mongo.ObjectID;
@@ -14,3 +14,30 @@ export type IAccessTokens = {
 	token: string;
 	hash: string;
 };
+
+/**
+ * AccessTokenを物理削除します
+ */
+export async function deleteAccessToken(accessToken: string | mongo.ObjectID | IAccessToken) {
+	let a: IAccessToken;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(accessToken)) {
+		a = await AccessToken.findOne({
+			_id: accessToken
+		});
+	} else if (typeof accessToken === 'string') {
+		a = await AccessToken.findOne({
+			_id: new mongo.ObjectID(accessToken)
+		});
+	} else {
+		a = accessToken as IAccessToken;
+	}
+
+	if (a == null) return;
+
+	// このAccessTokenを削除
+	await AccessToken.remove({
+		_id: a._id
+	});
+}
diff --git a/src/models/drive-file.ts b/src/models/drive-file.ts
index c86570f0f72dd03861af08d1eeea4ff9b1fcaadb..80fe8e030011310b9253a74dbcb1a9506a0ca44d 100644
--- a/src/models/drive-file.ts
+++ b/src/models/drive-file.ts
@@ -1,8 +1,11 @@
-import * as mongodb from 'mongodb';
+import * as mongo from 'mongodb';
 import deepcopy = require('deepcopy');
 import { pack as packFolder } from './drive-folder';
 import config from '../config';
 import monkDb, { nativeDbConn } from '../db/mongodb';
+import Note, { deleteNote } from './note';
+import MessagingMessage, { deleteMessagingMessage } from './messaging-message';
+import User from './user';
 
 const DriveFile = monkDb.get<IDriveFile>('driveFiles.files');
 
@@ -10,9 +13,9 @@ DriveFile.createIndex('metadata.uri', { sparse: true, unique: true });
 
 export default DriveFile;
 
-const getGridFSBucket = async (): Promise<mongodb.GridFSBucket> => {
+const getGridFSBucket = async (): Promise<mongo.GridFSBucket> => {
 	const db = await nativeDbConn();
-	const bucket = new mongodb.GridFSBucket(db, {
+	const bucket = new mongo.GridFSBucket(db, {
 		bucketName: 'driveFiles'
 	});
 	return bucket;
@@ -22,14 +25,14 @@ export { getGridFSBucket };
 
 export type IMetadata = {
 	properties: any;
-	userId: mongodb.ObjectID;
-	folderId: mongodb.ObjectID;
+	userId: mongo.ObjectID;
+	folderId: mongo.ObjectID;
 	comment: string;
 	uri: string;
 };
 
 export type IDriveFile = {
-	_id: mongodb.ObjectID;
+	_id: mongo.ObjectID;
 	uploadDate: Date;
 	md5: string;
 	filename: string;
@@ -47,12 +50,56 @@ export function validateFileName(name: string): boolean {
 	);
 }
 
+/**
+ * DriveFileを物理削除します
+ */
+export async function deleteDriveFile(driveFile: string | mongo.ObjectID | IDriveFile) {
+	let d: IDriveFile;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(driveFile)) {
+		d = await DriveFile.findOne({
+			_id: driveFile
+		});
+	} else if (typeof driveFile === 'string') {
+		d = await DriveFile.findOne({
+			_id: new mongo.ObjectID(driveFile)
+		});
+	} else {
+		d = driveFile as IDriveFile;
+	}
+
+	if (d == null) return;
+
+	// このDriveFileを添付しているNoteをすべて削除
+	await Promise.all((
+		await Note.find({ mediaIds: d._id })
+	).map(x => deleteNote(x)));
+
+	// このDriveFileを添付しているMessagingMessageをすべて削除
+	await Promise.all((
+		await MessagingMessage.find({ fileId: d._id })
+	).map(x => deleteMessagingMessage(x)));
+
+	// このDriveFileがアバターやバナーに使われていたらそれらのプロパティをnullにする
+	const u = await User.findOne({ _id: d.metadata.userId });
+	if (u) {
+		if (u.avatarId.equals(d._id)) {
+			await User.update({ _id: u._id }, { $set: { avatarId: null } });
+		}
+		if (u.bannerId.equals(d._id)) {
+			await User.update({ _id: u._id }, { $set: { bannerId: null } });
+		}
+	}
+
+	// このDriveFileを削除
+	await DriveFile.remove({
+		_id: d._id
+	});
+}
+
 /**
  * Pack a drive file for API response
- *
- * @param {any} file
- * @param {any} options?
- * @return {Promise<any>}
  */
 export const pack = (
 	file: any,
@@ -67,13 +114,13 @@ export const pack = (
 	let _file: any;
 
 	// Populate the file if 'file' is ID
-	if (mongodb.ObjectID.prototype.isPrototypeOf(file)) {
+	if (mongo.ObjectID.prototype.isPrototypeOf(file)) {
 		_file = await DriveFile.findOne({
 			_id: file
 		});
 	} else if (typeof file === 'string') {
 		_file = await DriveFile.findOne({
-			_id: new mongodb.ObjectID(file)
+			_id: new mongo.ObjectID(file)
 		});
 	} else {
 		_file = deepcopy(file);
diff --git a/src/models/drive-folder.ts b/src/models/drive-folder.ts
index 45cc9c9649e3ff47ae9b8f9eb3b8cc2fc876ae18..e7961936aac992d8eed717281d4db5e4b16adf92 100644
--- a/src/models/drive-folder.ts
+++ b/src/models/drive-folder.ts
@@ -21,12 +21,53 @@ export function isValidFolderName(name: string): boolean {
 	);
 }
 
+/**
+ * DriveFolderを物理削除します
+ */
+export async function deleteDriveFolder(driveFolder: string | mongo.ObjectID | IDriveFolder) {
+	let d: IDriveFolder;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(driveFolder)) {
+		d = await DriveFolder.findOne({
+			_id: driveFolder
+		});
+	} else if (typeof driveFolder === 'string') {
+		d = await DriveFolder.findOne({
+			_id: new mongo.ObjectID(driveFolder)
+		});
+	} else {
+		d = driveFolder as IDriveFolder;
+	}
+
+	if (d == null) return;
+
+	// このDriveFolderに格納されているDriveFileがあればすべてルートに移動
+	await DriveFile.update({
+		'metadata.folderId': d._id
+	}, {
+		$set: {
+			'metadata.folderId': null
+		}
+	});
+
+	// このDriveFolderに格納されているDriveFolderがあればすべてルートに移動
+	await DriveFolder.update({
+		parentId: d._id
+	}, {
+		$set: {
+			parentId: null
+		}
+	});
+
+	// このDriveFolderを削除
+	await DriveFolder.remove({
+		_id: d._id
+	});
+}
+
 /**
  * Pack a drive folder for API response
- *
- * @param {any} folder
- * @param {any} options?
- * @return {Promise<any>}
  */
 export const pack = (
 	folder: any,
diff --git a/src/models/favorite.ts b/src/models/favorite.ts
index 73f8881926140b2c019ac01078ee59eac823b8de..b2c5828088e400a923ab36c4e5ed3a971a144957 100644
--- a/src/models/favorite.ts
+++ b/src/models/favorite.ts
@@ -1,8 +1,8 @@
 import * as mongo from 'mongodb';
 import db from '../db/mongodb';
 
-const Favorites = db.get<IFavorite>('favorites');
-export default Favorites;
+const Favorite = db.get<IFavorite>('favorites');
+export default Favorite;
 
 export type IFavorite = {
 	_id: mongo.ObjectID;
@@ -10,3 +10,30 @@ export type IFavorite = {
 	userId: mongo.ObjectID;
 	noteId: mongo.ObjectID;
 };
+
+/**
+ * Favoriteを物理削除します
+ */
+export async function deleteFavorite(favorite: string | mongo.ObjectID | IFavorite) {
+	let f: IFavorite;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(favorite)) {
+		f = await Favorite.findOne({
+			_id: favorite
+		});
+	} else if (typeof favorite === 'string') {
+		f = await Favorite.findOne({
+			_id: new mongo.ObjectID(favorite)
+		});
+	} else {
+		f = favorite as IFavorite;
+	}
+
+	if (f == null) return;
+
+	// このFavoriteを削除
+	await Favorite.remove({
+		_id: f._id
+	});
+}
diff --git a/src/models/followed-log.ts b/src/models/followed-log.ts
index 9e3ca1782235988fbb7d526ca45aaae7264791e9..7d488b9cd353643b9189230c00109a6302ff0565 100644
--- a/src/models/followed-log.ts
+++ b/src/models/followed-log.ts
@@ -1,12 +1,39 @@
-import { ObjectID } from 'mongodb';
+import * as mongo from 'mongodb';
 import db from '../db/mongodb';
 
 const FollowedLog = db.get<IFollowedLog>('followedLogs');
 export default FollowedLog;
 
 export type IFollowedLog = {
-	_id: ObjectID;
+	_id: mongo.ObjectID;
 	createdAt: Date;
-	userId: ObjectID;
+	userId: mongo.ObjectID;
 	count: number;
 };
+
+/**
+ * FollowedLogを物理削除します
+ */
+export async function deleteFollowedLog(followedLog: string | mongo.ObjectID | IFollowedLog) {
+	let f: IFollowedLog;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(followedLog)) {
+		f = await FollowedLog.findOne({
+			_id: followedLog
+		});
+	} else if (typeof followedLog === 'string') {
+		f = await FollowedLog.findOne({
+			_id: new mongo.ObjectID(followedLog)
+		});
+	} else {
+		f = followedLog as IFollowedLog;
+	}
+
+	if (f == null) return;
+
+	// このFollowedLogを削除
+	await FollowedLog.remove({
+		_id: f._id
+	});
+}
diff --git a/src/models/following-log.ts b/src/models/following-log.ts
index 045ff7bf02234b3800fce1258db529b48e93c213..c06a337fd488ac6c45257b0f0f76618270595459 100644
--- a/src/models/following-log.ts
+++ b/src/models/following-log.ts
@@ -1,12 +1,39 @@
-import { ObjectID } from 'mongodb';
+import * as mongo from 'mongodb';
 import db from '../db/mongodb';
 
 const FollowingLog = db.get<IFollowingLog>('followingLogs');
 export default FollowingLog;
 
 export type IFollowingLog = {
-	_id: ObjectID;
+	_id: mongo.ObjectID;
 	createdAt: Date;
-	userId: ObjectID;
+	userId: mongo.ObjectID;
 	count: number;
 };
+
+/**
+ * FollowingLogを物理削除します
+ */
+export async function deleteFollowingLog(followingLog: string | mongo.ObjectID | IFollowingLog) {
+	let f: IFollowingLog;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(followingLog)) {
+		f = await FollowingLog.findOne({
+			_id: followingLog
+		});
+	} else if (typeof followingLog === 'string') {
+		f = await FollowingLog.findOne({
+			_id: new mongo.ObjectID(followingLog)
+		});
+	} else {
+		f = followingLog as IFollowingLog;
+	}
+
+	if (f == null) return;
+
+	// このFollowingLogを削除
+	await FollowingLog.remove({
+		_id: f._id
+	});
+}
diff --git a/src/models/following.ts b/src/models/following.ts
index b4090d8c7e0eb4ebb68c6662b0db9b54ea056c3e..f10e349ee9b25d51af9557bb839f8c735f3d6fad 100644
--- a/src/models/following.ts
+++ b/src/models/following.ts
@@ -11,3 +11,30 @@ export type IFollowing = {
 	followeeId: mongo.ObjectID;
 	followerId: mongo.ObjectID;
 };
+
+/**
+ * Followingを物理削除します
+ */
+export async function deleteFollowing(following: string | mongo.ObjectID | IFollowing) {
+	let f: IFollowing;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(following)) {
+		f = await Following.findOne({
+			_id: following
+		});
+	} else if (typeof following === 'string') {
+		f = await Following.findOne({
+			_id: new mongo.ObjectID(following)
+		});
+	} else {
+		f = following as IFollowing;
+	}
+
+	if (f == null) return;
+
+	// このFollowingを削除
+	await Following.remove({
+		_id: f._id
+	});
+}
diff --git a/src/models/messaging-history.ts b/src/models/messaging-history.ts
index 6864e22d2f3205d9e129e896e1dfdf68e58abdde..5367f81412ccbd758053d16d2ff93a92dc6e9c3f 100644
--- a/src/models/messaging-history.ts
+++ b/src/models/messaging-history.ts
@@ -11,3 +11,30 @@ export type IMessagingHistory = {
 	partnerId: mongo.ObjectID;
 	messageId: mongo.ObjectID;
 };
+
+/**
+ * MessagingHistoryを物理削除します
+ */
+export async function deleteMessagingHistory(messagingHistory: string | mongo.ObjectID | IMessagingHistory) {
+	let m: IMessagingHistory;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(messagingHistory)) {
+		m = await MessagingHistory.findOne({
+			_id: messagingHistory
+		});
+	} else if (typeof messagingHistory === 'string') {
+		m = await MessagingHistory.findOne({
+			_id: new mongo.ObjectID(messagingHistory)
+		});
+	} else {
+		m = messagingHistory as IMessagingHistory;
+	}
+
+	if (m == null) return;
+
+	// このMessagingHistoryを削除
+	await MessagingHistory.remove({
+		_id: m._id
+	});
+}
diff --git a/src/models/messaging-message.ts b/src/models/messaging-message.ts
index 974ee54ab8ab95bdeda8833a9bad4494edcd25c6..9d62fab4fae3b02532ca06426172b069cc886726 100644
--- a/src/models/messaging-message.ts
+++ b/src/models/messaging-message.ts
@@ -3,6 +3,7 @@ import deepcopy = require('deepcopy');
 import { pack as packUser } from './user';
 import { pack as packFile } from './drive-file';
 import db from '../db/mongodb';
+import MessagingHistory, { deleteMessagingHistory } from './messaging-history';
 
 const MessagingMessage = db.get<IMessagingMessage>('messagingMessages');
 export default MessagingMessage;
@@ -22,13 +23,40 @@ export function isValidText(text: string): boolean {
 	return text.length <= 1000 && text.trim() != '';
 }
 
+/**
+ * MessagingMessageを物理削除します
+ */
+export async function deleteMessagingMessage(messagingMessage: string | mongo.ObjectID | IMessagingMessage) {
+	let m: IMessagingMessage;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(messagingMessage)) {
+		m = await MessagingMessage.findOne({
+			_id: messagingMessage
+		});
+	} else if (typeof messagingMessage === 'string') {
+		m = await MessagingMessage.findOne({
+			_id: new mongo.ObjectID(messagingMessage)
+		});
+	} else {
+		m = messagingMessage as IMessagingMessage;
+	}
+
+	if (m == null) return;
+
+	// このMessagingMessageを指すMessagingHistoryをすべて削除
+	await Promise.all((
+		await MessagingHistory.find({ messageId: m._id })
+	).map(x => deleteMessagingHistory(x)));
+
+	// このMessagingMessageを削除
+	await MessagingMessage.remove({
+		_id: m._id
+	});
+}
+
 /**
  * Pack a messaging message for API response
- *
- * @param {any} message
- * @param {any} me?
- * @param {any} options?
- * @return {Promise<any>}
  */
 export const pack = (
 	message: any,
diff --git a/src/models/mute.ts b/src/models/mute.ts
index 879361596777574a66d7913237c2cf21406101a9..e068215c9494bcab54b018959bc58d4b76fd2a2e 100644
--- a/src/models/mute.ts
+++ b/src/models/mute.ts
@@ -11,3 +11,30 @@ export interface IMute {
 	muterId: mongo.ObjectID;
 	muteeId: mongo.ObjectID;
 }
+
+/**
+ * Muteを物理削除します
+ */
+export async function deleteMute(mute: string | mongo.ObjectID | IMute) {
+	let m: IMute;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(mute)) {
+		m = await Mute.findOne({
+			_id: mute
+		});
+	} else if (typeof mute === 'string') {
+		m = await Mute.findOne({
+			_id: new mongo.ObjectID(mute)
+		});
+	} else {
+		m = mute as IMute;
+	}
+
+	if (m == null) return;
+
+	// このMuteを削除
+	await Mute.remove({
+		_id: m._id
+	});
+}
diff --git a/src/models/note-reaction.ts b/src/models/note-reaction.ts
index d499442de95dd1be1ac557d74999f76368650700..9bf467f2220a1a9d0d1eb1f84b6eaaea113d067a 100644
--- a/src/models/note-reaction.ts
+++ b/src/models/note-reaction.ts
@@ -16,12 +16,35 @@ export interface INoteReaction {
 	reaction: string;
 }
 
+/**
+ * NoteReactionを物理削除します
+ */
+export async function deleteNoteReaction(noteReaction: string | mongo.ObjectID | INoteReaction) {
+	let n: INoteReaction;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(noteReaction)) {
+		n = await NoteReaction.findOne({
+			_id: noteReaction
+		});
+	} else if (typeof noteReaction === 'string') {
+		n = await NoteReaction.findOne({
+			_id: new mongo.ObjectID(noteReaction)
+		});
+	} else {
+		n = noteReaction as INoteReaction;
+	}
+
+	if (n == null) return;
+
+	// このNoteReactionを削除
+	await NoteReaction.remove({
+		_id: n._id
+	});
+}
+
 /**
  * Pack a reaction for API response
- *
- * @param {any} reaction
- * @param {any} me?
- * @return {Promise<any>}
  */
 export const pack = (
 	reaction: any,
diff --git a/src/models/note-watching.ts b/src/models/note-watching.ts
index b5ef3b61b7deb271dbfac7c136b6b7b36c9d5f02..479f92dd44a5e5b6eb89738c8b13c2c3e067f608 100644
--- a/src/models/note-watching.ts
+++ b/src/models/note-watching.ts
@@ -11,3 +11,30 @@ export interface INoteWatching {
 	userId: mongo.ObjectID;
 	noteId: mongo.ObjectID;
 }
+
+/**
+ * NoteWatchingを物理削除します
+ */
+export async function deleteNoteWatching(noteWatching: string | mongo.ObjectID | INoteWatching) {
+	let n: INoteWatching;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(noteWatching)) {
+		n = await NoteWatching.findOne({
+			_id: noteWatching
+		});
+	} else if (typeof noteWatching === 'string') {
+		n = await NoteWatching.findOne({
+			_id: new mongo.ObjectID(noteWatching)
+		});
+	} else {
+		n = noteWatching as INoteWatching;
+	}
+
+	if (n == null) return;
+
+	// このNoteWatchingを削除
+	await NoteWatching.remove({
+		_id: n._id
+	});
+}
diff --git a/src/models/note.ts b/src/models/note.ts
index f509fa66c83477cfd2efbd0ef9103e9f81a673ca..3c1c2e18e1c4419dc2c6740bacbc14126ff3c5c9 100644
--- a/src/models/note.ts
+++ b/src/models/note.ts
@@ -5,9 +5,13 @@ import db from '../db/mongodb';
 import { IUser, pack as packUser } from './user';
 import { pack as packApp } from './app';
 import { pack as packChannel } from './channel';
-import Vote from './poll-vote';
-import Reaction from './note-reaction';
+import Vote, { deletePollVote } from './poll-vote';
+import Reaction, { deleteNoteReaction } from './note-reaction';
 import { pack as packFile } from './drive-file';
+import NoteWatching, { deleteNoteWatching } from './note-watching';
+import NoteReaction from './note-reaction';
+import Favorite, { deleteFavorite } from './favorite';
+import PollVote from './poll-vote';
 
 const Note = db.get<INote>('notes');
 
@@ -69,6 +73,63 @@ export type INote = {
 	};
 };
 
+/**
+ * Noteを物理削除します
+ */
+export async function deleteNote(note: string | mongo.ObjectID | INote) {
+	let n: INote;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(note)) {
+		n = await Note.findOne({
+			_id: note
+		});
+	} else if (typeof note === 'string') {
+		n = await Note.findOne({
+			_id: new mongo.ObjectID(note)
+		});
+	} else {
+		n = note as INote;
+	}
+
+	if (n == null) return;
+
+	// このNoteへの返信をすべて削除
+	await Promise.all((
+		await Note.find({ replyId: n._id })
+	).map(x => deleteNote(x)));
+
+	// このNoteのRenoteをすべて削除
+	await Promise.all((
+		await Note.find({ renoteId: n._id })
+	).map(x => deleteNote(x)));
+
+	// この投稿に対するNoteWatchingをすべて削除
+	await Promise.all((
+		await NoteWatching.find({ noteId: n._id })
+	).map(x => deleteNoteWatching(x)));
+
+	// この投稿に対するNoteReactionをすべて削除
+	await Promise.all((
+		await NoteReaction.find({ noteId: n._id })
+	).map(x => deleteNoteReaction(x)));
+
+	// この投稿に対するPollVoteをすべて削除
+	await Promise.all((
+		await PollVote.find({ noteId: n._id })
+	).map(x => deletePollVote(x)));
+
+	// この投稿に対するFavoriteをすべて削除
+	await Promise.all((
+		await Favorite.find({ noteId: n._id })
+	).map(x => deleteFavorite(x)));
+
+	// このNoteを削除
+	await Note.remove({
+		_id: n._id
+	});
+}
+
 /**
  * Pack a note for API response
  *
diff --git a/src/models/poll-vote.ts b/src/models/poll-vote.ts
index 4d33b100e7bd8ce8d76077474045d71530a29f02..85c8454ddc8c9c0016559e41ce507a23cc2b6809 100644
--- a/src/models/poll-vote.ts
+++ b/src/models/poll-vote.ts
@@ -11,3 +11,30 @@ export interface IPollVote {
 	noteId: mongo.ObjectID;
 	choice: number;
 }
+
+/**
+ * PollVoteを物理削除します
+ */
+export async function deletePollVote(pollVote: string | mongo.ObjectID | IPollVote) {
+	let p: IPollVote;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(pollVote)) {
+		p = await PollVote.findOne({
+			_id: pollVote
+		});
+	} else if (typeof pollVote === 'string') {
+		p = await PollVote.findOne({
+			_id: new mongo.ObjectID(pollVote)
+		});
+	} else {
+		p = pollVote as IPollVote;
+	}
+
+	if (p == null) return;
+
+	// このPollVoteを削除
+	await PollVote.remove({
+		_id: p._id
+	});
+}
diff --git a/src/models/sw-subscription.ts b/src/models/sw-subscription.ts
index 743d0d2dd9a94dacf3c14032102b91bfb11fa59b..621ac8a9b6dea5f1be14e6cdbe3e02239aa94a54 100644
--- a/src/models/sw-subscription.ts
+++ b/src/models/sw-subscription.ts
@@ -11,3 +11,31 @@ export interface ISwSubscription {
 	auth: string;
 	publickey: string;
 }
+
+/**
+ * SwSubscriptionを物理削除します
+ */
+export async function deleteSwSubscription(swSubscription: string | mongo.ObjectID | ISwSubscription) {
+	let s: ISwSubscription;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(swSubscription)) {
+		s = await SwSubscription.findOne({
+			_id: swSubscription
+		});
+	} else if (typeof swSubscription === 'string') {
+		s = await SwSubscription.findOne({
+			_id: new mongo.ObjectID(swSubscription)
+		});
+	} else {
+		s = swSubscription as ISwSubscription;
+	}
+
+	if (s == null) return;
+
+	// このSwSubscriptionを削除
+	await SwSubscription.remove({
+		_id: s._id
+	});
+}
+
diff --git a/src/models/user.ts b/src/models/user.ts
index adc9e6da99102a98d332774dadb77009e06a7853..c121790c31ebe88c8d278dbf7f503a8295d6e510 100644
--- a/src/models/user.ts
+++ b/src/models/user.ts
@@ -2,15 +2,28 @@ import * as mongo from 'mongodb';
 import deepcopy = require('deepcopy');
 import rap from '@prezzemolo/rap';
 import db from '../db/mongodb';
-import { INote, pack as packNote } from './note';
-import Following from './following';
-import Mute from './mute';
+import Note, { INote, pack as packNote, deleteNote } from './note';
+import Following, { deleteFollowing } from './following';
+import Mute, { deleteMute } from './mute';
 import getFriends from '../server/api/common/get-friends';
 import config from '../config';
+import AccessToken, { deleteAccessToken } from './access-token';
+import NoteWatching, { deleteNoteWatching } from './note-watching';
+import Favorite, { deleteFavorite } from './favorite';
+import NoteReaction, { deleteNoteReaction } from './note-reaction';
+import MessagingMessage, { deleteMessagingMessage } from './messaging-message';
+import MessagingHistory, { deleteMessagingHistory } from './messaging-history';
+import DriveFile, { deleteDriveFile } from './drive-file';
+import DriveFolder, { deleteDriveFolder } from './drive-folder';
+import PollVote, { deletePollVote } from './poll-vote';
+import FollowingLog, { deleteFollowingLog } from './following-log';
+import FollowedLog, { deleteFollowedLog } from './followed-log';
+import SwSubscription, { deleteSwSubscription } from './sw-subscription';
 
 const User = db.get<IUser>('users');
 
 User.createIndex('username');
+User.createIndex('usernameLower');
 User.createIndex('token');
 User.createIndex('uri', { sparse: true, unique: true });
 
@@ -121,6 +134,120 @@ export function init(user): IUser {
 	return user;
 }
 
+/**
+ * Userを物理削除します
+ */
+export async function deleteUser(user: string | mongo.ObjectID | IUser) {
+	let u: IUser;
+
+	// Populate
+	if (mongo.ObjectID.prototype.isPrototypeOf(user)) {
+		u = await User.findOne({
+			_id: user
+		});
+	} else if (typeof user === 'string') {
+		u = await User.findOne({
+			_id: new mongo.ObjectID(user)
+		});
+	} else {
+		u = user as IUser;
+	}
+
+	if (u == null) return;
+
+	// このユーザーのAccessTokenをすべて削除
+	await Promise.all((
+		await AccessToken.find({ userId: u._id })
+	).map(x => deleteAccessToken(x)));
+
+	// このユーザーのNoteをすべて削除
+	await Promise.all((
+		await Note.find({ userId: u._id })
+	).map(x => deleteNote(x)));
+
+	// このユーザーのNoteReactionをすべて削除
+	await Promise.all((
+		await NoteReaction.find({ userId: u._id })
+	).map(x => deleteNoteReaction(x)));
+
+	// このユーザーのNoteWatchingをすべて削除
+	await Promise.all((
+		await NoteWatching.find({ userId: u._id })
+	).map(x => deleteNoteWatching(x)));
+
+	// このユーザーのPollVoteをすべて削除
+	await Promise.all((
+		await PollVote.find({ userId: u._id })
+	).map(x => deletePollVote(x)));
+
+	// このユーザーのFavoriteをすべて削除
+	await Promise.all((
+		await Favorite.find({ userId: u._id })
+	).map(x => deleteFavorite(x)));
+
+	// このユーザーのMessageをすべて削除
+	await Promise.all((
+		await MessagingMessage.find({ userId: u._id })
+	).map(x => deleteMessagingMessage(x)));
+
+	// このユーザーへのMessageをすべて削除
+	await Promise.all((
+		await MessagingMessage.find({ recipientId: u._id })
+	).map(x => deleteMessagingMessage(x)));
+
+	// このユーザーの関わるMessagingHistoryをすべて削除
+	await Promise.all((
+		await MessagingHistory.find({ $or: [{ partnerId: u._id }, { userId: u._id }] })
+	).map(x => deleteMessagingHistory(x)));
+
+	// このユーザーのDriveFileをすべて削除
+	await Promise.all((
+		await DriveFile.find({ 'metadata.userId': u._id })
+	).map(x => deleteDriveFile(x)));
+
+	// このユーザーのDriveFolderをすべて削除
+	await Promise.all((
+		await DriveFolder.find({ userId: u._id })
+	).map(x => deleteDriveFolder(x)));
+
+	// このユーザーのMuteをすべて削除
+	await Promise.all((
+		await Mute.find({ muterId: u._id })
+	).map(x => deleteMute(x)));
+
+	// このユーザーへのMuteをすべて削除
+	await Promise.all((
+		await Mute.find({ muteeId: u._id })
+	).map(x => deleteMute(x)));
+
+	// このユーザーのFollowingをすべて削除
+	await Promise.all((
+		await Following.find({ followerId: u._id })
+	).map(x => deleteFollowing(x)));
+
+	// このユーザーへのFollowingをすべて削除
+	await Promise.all((
+		await Following.find({ followeeId: u._id })
+	).map(x => deleteFollowing(x)));
+
+	// このユーザーのFollowingLogをすべて削除
+	await Promise.all((
+		await FollowingLog.find({ userId: u._id })
+	).map(x => deleteFollowingLog(x)));
+
+	// このユーザーのFollowedLogをすべて削除
+	await Promise.all((
+		await FollowedLog.find({ userId: u._id })
+	).map(x => deleteFollowedLog(x)));
+
+	// このユーザーのSwSubscriptionをすべて削除
+	await Promise.all((
+		await SwSubscription.find({ userId: u._id })
+	).map(x => deleteSwSubscription(x)));
+
+	// このユーザーを削除
+}
+
 /**
  * Pack a user for API response
  *
diff --git a/src/remote/activitypub/renderer/context.ts b/src/remote/activitypub/renderer/context.ts
deleted file mode 100644
index b56f727ae79ed994854f40d7c2289b446a14deb7..0000000000000000000000000000000000000000
--- a/src/remote/activitypub/renderer/context.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-export default [
-	'https://www.w3.org/ns/activitystreams',
-	'https://w3id.org/security/v1',
-	{ Hashtag: 'as:Hashtag' }
-];
diff --git a/src/remote/activitypub/renderer/index.ts b/src/remote/activitypub/renderer/index.ts
new file mode 100644
index 0000000000000000000000000000000000000000..ee7f496162c11471770a929ff5ddd671aafb4146
--- /dev/null
+++ b/src/remote/activitypub/renderer/index.ts
@@ -0,0 +1,7 @@
+export default (x: any) => Object.assign({
+	'@context': [
+		'https://www.w3.org/ns/activitystreams',
+		'https://w3id.org/security/v1',
+		{ Hashtag: 'as:Hashtag' }
+	]
+}, x);
diff --git a/src/server/activitypub.ts b/src/server/activitypub.ts
new file mode 100644
index 0000000000000000000000000000000000000000..2a99bccfc40eabf00e8eaf760c1c5a0bf857a61a
--- /dev/null
+++ b/src/server/activitypub.ts
@@ -0,0 +1,131 @@
+import * as Router from 'koa-router';
+import { parseRequest } from 'http-signature';
+
+import { createHttp } from '../queue';
+import pack from '../remote/activitypub/renderer';
+import Note from '../models/note';
+import User, { isLocalUser } from '../models/user';
+import renderNote from '../remote/activitypub/renderer/note';
+import renderKey from '../remote/activitypub/renderer/key';
+import renderPerson from '../remote/activitypub/renderer/person';
+import renderOrderedCollection from '../remote/activitypub/renderer/ordered-collection';
+//import parseAcct from '../acct/parse';
+import config from '../config';
+
+// Init router
+const router = new Router();
+
+//#region Routing
+
+// inbox
+router.post('/users/:user/inbox', ctx => {
+	let signature;
+
+	ctx.req.headers.authorization = 'Signature ' + ctx.req.headers.signature;
+
+	try {
+		signature = parseRequest(ctx.req);
+	} catch (e) {
+		ctx.status = 401;
+		return;
+	}
+
+	createHttp({
+		type: 'processInbox',
+		activity: ctx.request.body,
+		signature
+	}).save();
+
+	ctx.status = 202;
+});
+
+// note
+router.get('/notes/:note', async (ctx, next) => {
+	const accepted = ctx.accepts('html', 'application/activity+json', 'application/ld+json');
+	if (!['application/activity+json', 'application/ld+json'].includes(accepted as string)) {
+		await next();
+		return;
+	}
+
+	const note = await Note.findOne({
+		_id: ctx.params.note
+	});
+
+	if (note === null) {
+		ctx.status = 404;
+		return;
+	}
+
+	ctx.body = pack(await renderNote(note));
+});
+
+// outbot
+router.get('/users/:user/outbox', async ctx => {
+	const userId = ctx.params.user;
+
+	const user = await User.findOne({ _id: userId });
+
+	if (user === null) {
+		ctx.status = 404;
+		return;
+	}
+
+	const notes = await Note.find({ userId: user._id }, {
+		limit: 10,
+		sort: { _id: -1 }
+	});
+
+	const renderedNotes = await Promise.all(notes.map(note => renderNote(note)));
+	const rendered = renderOrderedCollection(`${config.url}/users/${userId}/inbox`, user.notesCount, renderedNotes);
+
+	ctx.body = pack(rendered);
+});
+
+// publickey
+router.get('/users/:user/publickey', async ctx => {
+	const userId = ctx.params.user;
+
+	const user = await User.findOne({ _id: userId });
+
+	if (user === null) {
+		ctx.status = 404;
+		return;
+	}
+
+	if (isLocalUser(user)) {
+		ctx.body = pack(renderKey(user));
+	} else {
+		ctx.status = 400;
+	}
+});
+
+// user
+router.get('/users/:user', async ctx => {
+	const userId = ctx.params.user;
+
+	const user = await User.findOne({ _id: userId });
+
+	if (user === null) {
+		ctx.status = 404;
+		return;
+	}
+
+	ctx.body = pack(renderPerson(user));
+});
+
+// follow form
+router.get('/authorize-follow', async ctx => {
+	/* TODO
+	const { username, host } = parseAcct(ctx.query.acct);
+	if (host === null) {
+		res.sendStatus(422);
+		return;
+	}
+
+	const finger = await request(`https://${host}`)
+	*/
+});
+
+//#endregion
+
+export default router;
diff --git a/src/server/activitypub/inbox.ts b/src/server/activitypub/inbox.ts
deleted file mode 100644
index 643d2945bd462f8d111170e4298fcc5be507a56e..0000000000000000000000000000000000000000
--- a/src/server/activitypub/inbox.ts
+++ /dev/null
@@ -1,32 +0,0 @@
-import * as bodyParser from 'body-parser';
-import * as express from 'express';
-import { parseRequest } from 'http-signature';
-import { createHttp } from '../../queue';
-
-const app = express.Router();
-
-app.post('/users/:user/inbox', bodyParser.json({
-	type() {
-		return true;
-	}
-}), async (req, res) => {
-	let signature;
-
-	req.headers.authorization = 'Signature ' + req.headers.signature;
-
-	try {
-		signature = parseRequest(req);
-	} catch (exception) {
-		return res.sendStatus(401);
-	}
-
-	createHttp({
-		type: 'processInbox',
-		activity: req.body,
-		signature,
-	}).save();
-
-	return res.status(202).end();
-});
-
-export default app;
diff --git a/src/server/activitypub/index.ts b/src/server/activitypub/index.ts
deleted file mode 100644
index 042579db9df5e6e3a21344a8d3f2617ec2362a10..0000000000000000000000000000000000000000
--- a/src/server/activitypub/index.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-import * as express from 'express';
-
-import user from './user';
-import inbox from './inbox';
-import outbox from './outbox';
-import publicKey from './publickey';
-import note from './note';
-
-const app = express();
-app.disable('x-powered-by');
-
-app.use(user);
-app.use(inbox);
-app.use(outbox);
-app.use(publicKey);
-app.use(note);
-
-export default app;
diff --git a/src/server/activitypub/note.ts b/src/server/activitypub/note.ts
deleted file mode 100644
index 1c2e695b80b621017629a32ced9288e4a3489f59..0000000000000000000000000000000000000000
--- a/src/server/activitypub/note.ts
+++ /dev/null
@@ -1,28 +0,0 @@
-import * as express from 'express';
-import context from '../../remote/activitypub/renderer/context';
-import render from '../../remote/activitypub/renderer/note';
-import Note from '../../models/note';
-
-const app = express.Router();
-
-app.get('/notes/:note', async (req, res, next) => {
-	const accepted = req.accepts(['html', 'application/activity+json', 'application/ld+json']);
-	if (!(['application/activity+json', 'application/ld+json'] as any[]).includes(accepted)) {
-		return next();
-	}
-
-	const note = await Note.findOne({
-		_id: req.params.note
-	});
-
-	if (note === null) {
-		return res.sendStatus(404);
-	}
-
-	const rendered = await render(note);
-	rendered['@context'] = context;
-
-	res.json(rendered);
-});
-
-export default app;
diff --git a/src/server/activitypub/outbox.ts b/src/server/activitypub/outbox.ts
deleted file mode 100644
index 1c97c17a2ee595b992ab34ea7aecfaebbec7d1e4..0000000000000000000000000000000000000000
--- a/src/server/activitypub/outbox.ts
+++ /dev/null
@@ -1,28 +0,0 @@
-import * as express from 'express';
-import context from '../../remote/activitypub/renderer/context';
-import renderNote from '../../remote/activitypub/renderer/note';
-import renderOrderedCollection from '../../remote/activitypub/renderer/ordered-collection';
-import config from '../../config';
-import Note from '../../models/note';
-import User from '../../models/user';
-
-const app = express.Router();
-
-app.get('/users/:user/outbox', async (req, res) => {
-	const userId = req.params.user;
-
-	const user = await User.findOne({ _id: userId });
-
-	const notes = await Note.find({ userId: user._id }, {
-		limit: 20,
-		sort: { _id: -1 }
-	});
-
-	const renderedNotes = await Promise.all(notes.map(note => renderNote(note)));
-	const rendered = renderOrderedCollection(`${config.url}/users/${userId}/inbox`, user.notesCount, renderedNotes);
-	rendered['@context'] = context;
-
-	res.json(rendered);
-});
-
-export default app;
diff --git a/src/server/activitypub/publickey.ts b/src/server/activitypub/publickey.ts
deleted file mode 100644
index e874b8272976df4cc0c5a3ce8091010dafc3b1eb..0000000000000000000000000000000000000000
--- a/src/server/activitypub/publickey.ts
+++ /dev/null
@@ -1,23 +0,0 @@
-import * as express from 'express';
-import context from '../../remote/activitypub/renderer/context';
-import render from '../../remote/activitypub/renderer/key';
-import User, { isLocalUser } from '../../models/user';
-
-const app = express.Router();
-
-app.get('/users/:user/publickey', async (req, res) => {
-	const userId = req.params.user;
-
-	const user = await User.findOne({ _id: userId });
-
-	if (isLocalUser(user)) {
-		const rendered = render(user);
-		rendered['@context'] = context;
-
-		res.json(rendered);
-	} else {
-		res.sendStatus(400);
-	}
-});
-
-export default app;
diff --git a/src/server/activitypub/user.ts b/src/server/activitypub/user.ts
deleted file mode 100644
index 9e98e92b6ab039a92cf5773dfffd4ba93c846f94..0000000000000000000000000000000000000000
--- a/src/server/activitypub/user.ts
+++ /dev/null
@@ -1,19 +0,0 @@
-import * as express from 'express';
-import context from '../../remote/activitypub/renderer/context';
-import render from '../../remote/activitypub/renderer/person';
-import User from '../../models/user';
-
-const app = express.Router();
-
-app.get('/users/:user', async (req, res) => {
-	const userId = req.params.user;
-
-	const user = await User.findOne({ _id: userId });
-
-	const rendered = render(user);
-	rendered['@context'] = context;
-
-	res.json(rendered);
-});
-
-export default app;
diff --git a/src/server/api/api-handler.ts b/src/server/api/api-handler.ts
index 409069b6a03315d4a58f2b6be1aa0bec09ecb34d..e716dcdc01d327b108d757e1f1f41294bf345b1c 100644
--- a/src/server/api/api-handler.ts
+++ b/src/server/api/api-handler.ts
@@ -1,4 +1,4 @@
-import * as express from 'express';
+import * as Koa from 'koa';
 
 import { Endpoint } from './endpoints';
 import authenticate from './authenticate';
@@ -6,16 +6,19 @@ import call from './call';
 import { IUser } from '../../models/user';
 import { IApp } from '../../models/app';
 
-export default async (endpoint: Endpoint, req: express.Request, res: express.Response) => {
+export default async (endpoint: Endpoint, ctx: Koa.Context) => {
+	const body = ctx.is('multipart/form-data') ? (ctx.req as any).body : ctx.request.body;
+
 	const reply = (x?: any, y?: any) => {
 		if (x === undefined) {
-			res.sendStatus(204);
+			ctx.status = 204;
 		} else if (typeof x === 'number') {
-			res.status(x).send({
+			ctx.status = x;
+			ctx.body = {
 				error: x === 500 ? 'INTERNAL_ERROR' : y
-			});
+			};
 		} else {
-			res.send(x);
+			ctx.body = x;
 		}
 	};
 
@@ -24,11 +27,21 @@ export default async (endpoint: Endpoint, req: express.Request, res: express.Res
 
 	// Authentication
 	try {
-		[user, app] = await authenticate(req.body['i']);
+		[user, app] = await authenticate(body['i']);
 	} catch (e) {
-		return reply(403, 'AUTHENTICATION_FAILED');
+		reply(403, 'AUTHENTICATION_FAILED');
+		return;
 	}
 
+	let res;
+
 	// API invoking
-	call(endpoint, user, app, req.body, req).then(reply).catch(e => reply(400, e));
+	try {
+		res = await call(endpoint, user, app, body, (ctx.req as any).file);
+	} catch (e) {
+		reply(400, e);
+		return;
+	}
+
+	reply(res);
 };
diff --git a/src/server/api/bot/interfaces/line.ts b/src/server/api/bot/interfaces/line.ts
index be3bfe33d322d61dc31965423368c81d66b2c0cb..733315391d561801f6876a86931eb921ca05079f 100644
--- a/src/server/api/bot/interfaces/line.ts
+++ b/src/server/api/bot/interfaces/line.ts
@@ -1,5 +1,5 @@
 import * as EventEmitter from 'events';
-import * as express from 'express';
+import * as Router from 'koa-router';
 import * as request from 'request';
 import * as crypto from 'crypto';
 import User from '../../../../models/user';
@@ -158,82 +158,81 @@ class LineBot extends BotCore {
 	}
 }
 
-module.exports = async (app: express.Application) => {
-	if (config.line_bot == null) return;
+const handler = new EventEmitter();
 
-	const handler = new EventEmitter();
+handler.on('event', async (ev) => {
 
-	handler.on('event', async (ev) => {
+	const sourceId = ev.source.userId;
+	const sessionId = `line-bot-sessions:${sourceId}`;
 
-		const sourceId = ev.source.userId;
-		const sessionId = `line-bot-sessions:${sourceId}`;
+	const session = await redis.get(sessionId);
+	let bot: LineBot;
 
-		const session = await redis.get(sessionId);
-		let bot: LineBot;
-
-		if (session == null) {
-			const user = await User.findOne({
-				host: null,
-				'line': {
-					userId: sourceId
-				}
-			});
+	if (session == null) {
+		const user = await User.findOne({
+			host: null,
+			'line': {
+				userId: sourceId
+			}
+		});
 
-			bot = new LineBot(user);
+		bot = new LineBot(user);
 
-			bot.on('signin', user => {
-				User.update(user._id, {
-					$set: {
-						'line': {
-							userId: sourceId
-						}
+		bot.on('signin', user => {
+			User.update(user._id, {
+				$set: {
+					'line': {
+						userId: sourceId
 					}
-				});
+				}
 			});
+		});
 
-			bot.on('signout', user => {
-				User.update(user._id, {
-					$set: {
-						'line': {
-							userId: null
-						}
+		bot.on('signout', user => {
+			User.update(user._id, {
+				$set: {
+					'line': {
+						userId: null
 					}
-				});
+				}
 			});
-
-			redis.set(sessionId, JSON.stringify(bot.export()));
-		} else {
-			bot = LineBot.import(JSON.parse(session));
-		}
-
-		bot.on('updated', () => {
-			redis.set(sessionId, JSON.stringify(bot.export()));
 		});
 
-		if (session != null) bot.refreshUser();
+		redis.set(sessionId, JSON.stringify(bot.export()));
+	} else {
+		bot = LineBot.import(JSON.parse(session));
+	}
 
-		bot.react(ev);
+	bot.on('updated', () => {
+		redis.set(sessionId, JSON.stringify(bot.export()));
 	});
 
-	app.post('/hooks/line', (req, res, next) => {
-		// req.headers['x-line-signature'] は常に string ですが、型定義の都合上
-		// string | string[] になっているので string を明示しています
-		const sig1 = req.headers['x-line-signature'] as string;
+	if (session != null) bot.refreshUser();
+
+	bot.react(ev);
+});
+
+// Init router
+const router = new Router();
+
+if (config.line_bot) {
+	router.post('/hooks/line', ctx => {
+		const sig1 = ctx.headers['x-line-signature'];
 
 		const hash = crypto.createHmac('SHA256', config.line_bot.channel_secret)
-			.update((req as any).rawBody);
+			.update(ctx.request.rawBody);
 
 		const sig2 = hash.digest('base64');
 
 		// シグネチャ比較
 		if (sig1 === sig2) {
-			req.body.events.forEach(ev => {
+			ctx.request.body.events.forEach(ev => {
 				handler.emit('event', ev);
 			});
-
-			res.sendStatus(200);
 		} else {
-			res.sendStatus(400);
+			ctx.status = 400;
 		}
 	});
-};
+}
+
+module.exports = router;
diff --git a/src/server/api/call.ts b/src/server/api/call.ts
index 1bfe94bb7494f301cbd259ab4c9f8c8b1ce16d1c..fd3cea77430a53661d0250271d88a09f387ad1fb 100644
--- a/src/server/api/call.ts
+++ b/src/server/api/call.ts
@@ -1,15 +1,11 @@
-import * as express from 'express';
-
 import endpoints, { Endpoint } from './endpoints';
 import limitter from './limitter';
 import { IUser } from '../../models/user';
 import { IApp } from '../../models/app';
 
-export default (endpoint: string | Endpoint, user: IUser, app: IApp, data: any, req?: express.Request) => new Promise(async (ok, rej) => {
+export default (endpoint: string | Endpoint, user: IUser, app: IApp, data: any, file?: any) => new Promise<any>(async (ok, rej) => {
 	const isSecure = user != null && app == null;
 
-	//console.log(endpoint, user, app, data);
-
 	const ep = typeof endpoint == 'string' ? endpoints.find(e => e.name == endpoint) : endpoint;
 
 	if (ep.secure && !isSecure) {
@@ -37,8 +33,8 @@ export default (endpoint: string | Endpoint, user: IUser, app: IApp, data: any,
 
 	let exec = require(`${__dirname}/endpoints/${ep.name}`);
 
-	if (ep.withFile && req) {
-		exec = exec.bind(null, req.file);
+	if (ep.withFile && file) {
+		exec = exec.bind(null, file);
 	}
 
 	let res;
diff --git a/src/server/api/common/signin.ts b/src/server/api/common/signin.ts
index 8bb327694d0943927931eec02630cced8d4d70f5..44e1336f271f89ae1881f9828b272203b03890fb 100644
--- a/src/server/api/common/signin.ts
+++ b/src/server/api/common/signin.ts
@@ -1,19 +1,22 @@
+import * as Koa from 'koa';
+
 import config from '../../../config';
+import { ILocalUser } from '../../../models/user';
 
-export default function(res, user, redirect: boolean) {
+export default function(ctx: Koa.Context, user: ILocalUser, redirect = false) {
 	const expires = 1000 * 60 * 60 * 24 * 365; // One Year
-	res.cookie('i', user.token, {
+	ctx.cookies.set('i', user.token, {
 		path: '/',
-		domain: `.${config.hostname}`,
-		secure: config.url.substr(0, 5) === 'https',
+		domain: config.hostname,
+		secure: config.url.startsWith('https'),
 		httpOnly: false,
 		expires: new Date(Date.now() + expires),
 		maxAge: expires
 	});
 
 	if (redirect) {
-		res.redirect(config.url);
+		ctx.redirect(config.url);
 	} else {
-		res.sendStatus(204);
+		ctx.status = 204;
 	}
 }
diff --git a/src/server/api/index.ts b/src/server/api/index.ts
index 5fbacd8a0eb8b60b7a6c94f473e129799e9a3d14..009c99acaeb99342a61bd89db85e0e4dcd5d5a52 100644
--- a/src/server/api/index.ts
+++ b/src/server/api/index.ts
@@ -2,53 +2,46 @@
  * API Server
  */
 
-import * as express from 'express';
-import * as bodyParser from 'body-parser';
-import * as cors from 'cors';
-import * as multer from 'multer';
+import * as Koa from 'koa';
+import * as Router from 'koa-router';
+import * as multer from 'koa-multer';
+import * as bodyParser from 'koa-bodyparser';
 
 import endpoints from './endpoints';
 
-/**
- * Init app
- */
-const app = express();
-
-app.disable('x-powered-by');
-app.set('etag', false);
-app.use(bodyParser.urlencoded({ extended: true }));
-app.use(bodyParser.json({
-	type: ['application/json', 'text/plain'],
-	verify: (req, res, buf, encoding) => {
-		if (buf && buf.length) {
-			(req as any).rawBody = buf.toString(encoding || 'utf8');
-		}
-	}
+const handler = require('./api-handler').default;
+
+// Init app
+const app = new Koa();
+app.use(bodyParser({
+	// リクエストが multipart/form-data でない限りはJSONだと見なす
+	detectJSON: ctx => !ctx.is('multipart/form-data')
 }));
-app.use(cors());
 
-app.get('/', (req, res) => {
-	res.send('YEE HAW');
+// Init multer instance
+const upload = multer({
+	storage: multer.diskStorage({})
 });
 
+// Init router
+const router = new Router();
+
 /**
  * Register endpoint handlers
  */
-endpoints.forEach(endpoint =>
-	endpoint.withFile ?
-		app.post(`/${endpoint.name}`,
-			endpoint.withFile ? multer({ storage: multer.diskStorage({}) }).single('file') : null,
-			require('./api-handler').default.bind(null, endpoint)) :
-		app.post(`/${endpoint.name}`,
-			require('./api-handler').default.bind(null, endpoint))
+endpoints.forEach(endpoint => endpoint.withFile
+	? router.post(`/${endpoint.name}`, upload.single('file'), handler.bind(null, endpoint))
+	: router.post(`/${endpoint.name}`, handler.bind(null, endpoint))
 );
 
-app.post('/signup', require('./private/signup').default);
-app.post('/signin', require('./private/signin').default);
+router.post('/signup', require('./private/signup').default);
+router.post('/signin', require('./private/signin').default);
 
-require('./service/github')(app);
-require('./service/twitter')(app);
+router.use(require('./service/github').routes());
+router.use(require('./service/twitter').routes());
+router.use(require('./bot/interfaces/line').routes());
 
-require('./bot/interfaces/line')(app);
+// Register router
+app.use(router.routes());
 
 module.exports = app;
diff --git a/src/server/api/private/signin.ts b/src/server/api/private/signin.ts
index 665ee21ebd8c3192fc4fbc17b502ca3ce142f764..5450c7ad27a76d18510794b95e7e03ba85692efc 100644
--- a/src/server/api/private/signin.ts
+++ b/src/server/api/private/signin.ts
@@ -1,4 +1,4 @@
-import * as express from 'express';
+import * as Koa from 'koa';
 import * as bcrypt from 'bcryptjs';
 import * as speakeasy from 'speakeasy';
 import User, { ILocalUser } from '../../../models/user';
@@ -7,26 +7,26 @@ import event from '../../../publishers/stream';
 import signin from '../common/signin';
 import config from '../../../config';
 
-export default async (req: express.Request, res: express.Response) => {
-	res.header('Access-Control-Allow-Origin', config.url);
-	res.header('Access-Control-Allow-Credentials', 'true');
+export default async (ctx: Koa.Context) => {
+	ctx.set('Access-Control-Allow-Origin', config.url);
+	ctx.set('Access-Control-Allow-Credentials', 'true');
 
-	const username = req.body['username'];
-	const password = req.body['password'];
-	const token = req.body['token'];
+	const username = ctx.request.body['username'];
+	const password = ctx.request.body['password'];
+	const token = ctx.request.body['token'];
 
 	if (typeof username != 'string') {
-		res.sendStatus(400);
+		ctx.status = 400;
 		return;
 	}
 
 	if (typeof password != 'string') {
-		res.sendStatus(400);
+		ctx.status = 400;
 		return;
 	}
 
 	if (token != null && typeof token != 'string') {
-		res.sendStatus(400);
+		ctx.status = 400;
 		return;
 	}
 
@@ -37,12 +37,12 @@ export default async (req: express.Request, res: express.Response) => {
 	}, {
 		fields: {
 			data: false,
-			'profile': false
+			profile: false
 		}
 	}) as ILocalUser;
 
 	if (user === null) {
-		res.status(404).send({
+		ctx.throw(404, {
 			error: 'user not found'
 		});
 		return;
@@ -60,17 +60,17 @@ export default async (req: express.Request, res: express.Response) => {
 			});
 
 			if (verified) {
-				signin(res, user, false);
+				signin(ctx, user);
 			} else {
-				res.status(400).send({
+				ctx.throw(400, {
 					error: 'invalid token'
 				});
 			}
 		} else {
-			signin(res, user, false);
+			signin(ctx, user);
 		}
 	} else {
-		res.status(400).send({
+		ctx.throw(400, {
 			error: 'incorrect password'
 		});
 	}
@@ -79,8 +79,8 @@ export default async (req: express.Request, res: express.Response) => {
 	const record = await Signin.insert({
 		createdAt: new Date(),
 		userId: user._id,
-		ip: req.ip,
-		headers: req.headers,
+		ip: ctx.ip,
+		headers: ctx.headers,
 		success: same
 	});
 
diff --git a/src/server/api/private/signup.ts b/src/server/api/private/signup.ts
index f441e1b754e90c0c0187b4e3556e330366b0238e..15257b869f316d09151f2381cf552f4059be6f95 100644
--- a/src/server/api/private/signup.ts
+++ b/src/server/api/private/signup.ts
@@ -1,5 +1,5 @@
 import * as uuid from 'uuid';
-import * as express from 'express';
+import * as Koa from 'koa';
 import * as bcrypt from 'bcryptjs';
 import { generate as generateKeypair } from '../../../crypto_key';
 import recaptcha = require('recaptcha-promise');
@@ -33,30 +33,30 @@ const home = {
 	]
 };
 
-export default async (req: express.Request, res: express.Response) => {
+export default async (ctx: Koa.Context) => {
 	// Verify recaptcha
 	// ただしテスト時はこの機構は障害となるため無効にする
 	if (process.env.NODE_ENV !== 'test') {
-		const success = await recaptcha(req.body['g-recaptcha-response']);
+		const success = await recaptcha(ctx.request.body['g-recaptcha-response']);
 
 		if (!success) {
-			res.status(400).send('recaptcha-failed');
+			ctx.throw(400, 'recaptcha-failed');
 			return;
 		}
 	}
 
-	const username = req.body['username'];
-	const password = req.body['password'];
+	const username = ctx.request.body['username'];
+	const password = ctx.request.body['password'];
 
 	// Validate username
 	if (!validateUsername(username)) {
-		res.sendStatus(400);
+		ctx.status = 400;
 		return;
 	}
 
 	// Validate password
 	if (!validatePassword(password)) {
-		res.sendStatus(400);
+		ctx.status = 400;
 		return;
 	}
 
@@ -71,7 +71,7 @@ export default async (req: express.Request, res: express.Response) => {
 
 	// Check username already used
 	if (usernameExist !== 0) {
-		res.sendStatus(400);
+		ctx.status = 400;
 		return;
 	}
 
@@ -143,5 +143,5 @@ export default async (req: express.Request, res: express.Response) => {
 	});
 
 	// Response
-	res.send(await pack(account));
+	ctx.body = await pack(account);
 };
diff --git a/src/server/api/service/github.ts b/src/server/api/service/github.ts
index bc8d3c6a7d562c273aa9cc5658b73e2b1f18aa4a..cd9760a36d4e1e45366d54be9022d87dd3cd6077 100644
--- a/src/server/api/service/github.ts
+++ b/src/server/api/service/github.ts
@@ -1,140 +1,156 @@
 import * as EventEmitter from 'events';
-import * as express from 'express';
+import * as Router from 'koa-router';
 import * as request from 'request';
 const crypto = require('crypto');
 
-import User from '../../../models/user';
+import User, { IUser } from '../../../models/user';
 import createNote from '../../../services/note/create';
 import config from '../../../config';
 
-module.exports = async (app: express.Application) => {
-	if (config.github_bot == null) return;
+const handler = new EventEmitter();
 
-	const bot = await User.findOne({
-		usernameLower: config.github_bot.username.toLowerCase()
-	});
+let bot: IUser;
 
+const post = async text => {
 	if (bot == null) {
-		console.warn(`GitHub hook bot specified, but not found: @${config.github_bot.username}`);
-		return;
+		const account = await User.findOne({
+			usernameLower: config.github_bot.username.toLowerCase()
+		});
+
+		if (account == null) {
+			console.warn(`GitHub hook bot specified, but not found: @${config.github_bot.username}`);
+			return;
+		} else {
+			bot = account;
+		}
 	}
 
-	const post = text => createNote(bot, { text });
+	createNote(bot, { text });
+};
+
+// Init router
+const router = new Router();
+
+if (config.github_bot != null) {
+	const secret = config.github_bot.hook_secret;
 
-	const handler = new EventEmitter();
+	router.post('/hooks/github', ctx => {
+		const body = JSON.stringify(ctx.request.body);
+		const hash = crypto.createHmac('sha1', secret).update(body).digest('hex');
+		const sig1 = new Buffer(ctx.headers['x-hub-signature']);
+		const sig2 = new Buffer(`sha1=${hash}`);
 
-	app.post('/hooks/github', (req, res, next) => {
-		// req.headers['x-hub-signature'] および
-		// req.headers['x-github-event'] は常に string ですが、型定義の都合上
-		// string | string[] になっているので string を明示しています
-		if ((new Buffer(req.headers['x-hub-signature'] as string)).equals(new Buffer(`sha1=${crypto.createHmac('sha1', config.github_bot.hook_secret).update(JSON.stringify(req.body)).digest('hex')}`))) {
-			handler.emit(req.headers['x-github-event'] as string, req.body);
-			res.sendStatus(200);
+		// シグネチャ比較
+		if (sig1.equals(sig2)) {
+			handler.emit(ctx.headers['x-github-event'], ctx.request.body);
+			ctx.status = 204;
 		} else {
-			res.sendStatus(400);
+			ctx.status = 400;
 		}
 	});
+}
 
-	handler.on('status', event => {
-		const state = event.state;
-		switch (state) {
-			case 'error':
-			case 'failure':
-				const commit = event.commit;
-				const parent = commit.parents[0];
-
-				// Fetch parent status
-				request({
-					url: `${parent.url}/statuses`,
-					headers: {
-						'User-Agent': 'misskey'
-					}
-				}, (err, res, body) => {
-					if (err) {
-						console.error(err);
-						return;
-					}
-					const parentStatuses = JSON.parse(body);
-					const parentState = parentStatuses[0].state;
-					const stillFailed = parentState == 'failure' || parentState == 'error';
-					if (stillFailed) {
-						post(`**⚠️BUILD STILL FAILED⚠️**: ?[${commit.commit.message}](${commit.html_url})`);
-					} else {
-						post(`**🚨BUILD FAILED🚨**: →→→?[${commit.commit.message}](${commit.html_url})←←←`);
-					}
-				});
-				break;
-		}
-	});
+module.exports = router;
 
-	handler.on('push', event => {
-		const ref = event.ref;
-		switch (ref) {
-			case 'refs/heads/master':
-				const pusher = event.pusher;
-				const compare = event.compare;
-				const commits = event.commits;
-				post([
-					`Pushed by **${pusher.name}** with ?[${commits.length} commit${commits.length > 1 ? 's' : ''}](${compare}):`,
-					commits.reverse().map(commit => `・[?[${commit.id.substr(0, 7)}](${commit.url})] ${commit.message.split('\n')[0]}`).join('\n'),
-				].join('\n'));
-				break;
-			case 'refs/heads/release':
-				const commit = event.commits[0];
-				post(`RELEASED: ${commit.message}`);
-				break;
-		}
-	});
+handler.on('status', event => {
+	const state = event.state;
+	switch (state) {
+		case 'error':
+		case 'failure':
+			const commit = event.commit;
+			const parent = commit.parents[0];
 
-	handler.on('issues', event => {
-		const issue = event.issue;
-		const action = event.action;
-		let title: string;
-		switch (action) {
-			case 'opened': title = 'Issue opened'; break;
-			case 'closed': title = 'Issue closed'; break;
-			case 'reopened': title = 'Issue reopened'; break;
-			default: return;
-		}
-		post(`${title}: <${issue.number}>「${issue.title}」\n${issue.html_url}`);
-	});
+			// Fetch parent status
+			request({
+				url: `${parent.url}/statuses`,
+				headers: {
+					'User-Agent': 'misskey'
+				}
+			}, (err, res, body) => {
+				if (err) {
+					console.error(err);
+					return;
+				}
+				const parentStatuses = JSON.parse(body);
+				const parentState = parentStatuses[0].state;
+				const stillFailed = parentState == 'failure' || parentState == 'error';
+				if (stillFailed) {
+					post(`**⚠️BUILD STILL FAILED⚠️**: ?[${commit.commit.message}](${commit.html_url})`);
+				} else {
+					post(`**🚨BUILD FAILED🚨**: →→→?[${commit.commit.message}](${commit.html_url})←←←`);
+				}
+			});
+			break;
+	}
+});
 
-	handler.on('issue_comment', event => {
-		const issue = event.issue;
-		const comment = event.comment;
-		const action = event.action;
-		let text: string;
-		switch (action) {
-			case 'created': text = `Commented to「${issue.title}」:${comment.user.login}「${comment.body}」\n${comment.html_url}`; break;
-			default: return;
-		}
-		post(text);
-	});
+handler.on('push', event => {
+	const ref = event.ref;
+	switch (ref) {
+		case 'refs/heads/master':
+			const pusher = event.pusher;
+			const compare = event.compare;
+			const commits = event.commits;
+			post([
+				`Pushed by **${pusher.name}** with ?[${commits.length} commit${commits.length > 1 ? 's' : ''}](${compare}):`,
+				commits.reverse().map(commit => `・[?[${commit.id.substr(0, 7)}](${commit.url})] ${commit.message.split('\n')[0]}`).join('\n'),
+			].join('\n'));
+			break;
+		case 'refs/heads/release':
+			const commit = event.commits[0];
+			post(`RELEASED: ${commit.message}`);
+			break;
+	}
+});
 
-	handler.on('watch', event => {
-		const sender = event.sender;
-		post(`⭐️ Starred by **${sender.login}** ⭐️`);
-	});
+handler.on('issues', event => {
+	const issue = event.issue;
+	const action = event.action;
+	let title: string;
+	switch (action) {
+		case 'opened': title = 'Issue opened'; break;
+		case 'closed': title = 'Issue closed'; break;
+		case 'reopened': title = 'Issue reopened'; break;
+		default: return;
+	}
+	post(`${title}: <${issue.number}>「${issue.title}」\n${issue.html_url}`);
+});
 
-	handler.on('fork', event => {
-		const repo = event.forkee;
-		post(`🍴 Forked:\n${repo.html_url} 🍴`);
-	});
+handler.on('issue_comment', event => {
+	const issue = event.issue;
+	const comment = event.comment;
+	const action = event.action;
+	let text: string;
+	switch (action) {
+		case 'created': text = `Commented to「${issue.title}」:${comment.user.login}「${comment.body}」\n${comment.html_url}`; break;
+		default: return;
+	}
+	post(text);
+});
 
-	handler.on('pull_request', event => {
-		const pr = event.pull_request;
-		const action = event.action;
-		let text: string;
-		switch (action) {
-			case 'opened': text = `New Pull Request:「${pr.title}」\n${pr.html_url}`; break;
-			case 'reopened': text = `Pull Request Reopened:「${pr.title}」\n${pr.html_url}`; break;
-			case 'closed':
-				text = pr.merged
-					? `Pull Request Merged!:「${pr.title}」\n${pr.html_url}`
-					: `Pull Request Closed:「${pr.title}」\n${pr.html_url}`;
-				break;
-			default: return;
-		}
-		post(text);
-	});
-};
+handler.on('watch', event => {
+	const sender = event.sender;
+	post(`⭐️ Starred by **${sender.login}** ⭐️`);
+});
+
+handler.on('fork', event => {
+	const repo = event.forkee;
+	post(`🍴 Forked:\n${repo.html_url} 🍴`);
+});
+
+handler.on('pull_request', event => {
+	const pr = event.pull_request;
+	const action = event.action;
+	let text: string;
+	switch (action) {
+		case 'opened': text = `New Pull Request:「${pr.title}」\n${pr.html_url}`; break;
+		case 'reopened': text = `Pull Request Reopened:「${pr.title}」\n${pr.html_url}`; break;
+		case 'closed':
+			text = pr.merged
+				? `Pull Request Merged!:「${pr.title}」\n${pr.html_url}`
+				: `Pull Request Closed:「${pr.title}」\n${pr.html_url}`;
+			break;
+		default: return;
+	}
+	post(text);
+});
diff --git a/src/server/api/service/twitter.ts b/src/server/api/service/twitter.ts
index e5239fa1713bf3ccb778c2aefbbf04c382bf47ba..9fb01b44efe4f701d0ea3bca6d5648679499689f 100644
--- a/src/server/api/service/twitter.ts
+++ b/src/server/api/service/twitter.ts
@@ -1,160 +1,155 @@
-import * as express from 'express';
-import * as cookie from 'cookie';
+import * as Koa from 'koa';
+import * as Router from 'koa-router';
 import * as uuid from 'uuid';
-// import * as Twitter from 'twitter';
-// const Twitter = require('twitter');
 import autwh from 'autwh';
 import redis from '../../../db/redis';
-import User, { pack } from '../../../models/user';
+import User, { pack, ILocalUser } from '../../../models/user';
 import event from '../../../publishers/stream';
 import config from '../../../config';
 import signin from '../common/signin';
 
-module.exports = (app: express.Application) => {
-	function getUserToken(req: express.Request) {
-		// req.headers['cookie'] は常に string ですが、型定義の都合上
-		// string | string[] になっているので string を明示しています
-		return ((req.headers['cookie'] as string || '').match(/i=(!\w+)/) || [null, null])[1];
-	}
-
-	function compareOrigin(req: express.Request) {
-		function normalizeUrl(url: string) {
-			return url[url.length - 1] === '/' ? url.substr(0, url.length - 1) : url;
-		}
-
-		// req.headers['referer'] は常に string ですが、型定義の都合上
-		// string | string[] になっているので string を明示しています
-		const referer = req.headers['referer'] as string;
+function getUserToken(ctx: Koa.Context) {
+	return ((ctx.headers['cookie'] || '').match(/i=(!\w+)/) || [null, null])[1];
+}
 
-		return (normalizeUrl(referer) == normalizeUrl(config.url));
+function compareOrigin(ctx: Koa.Context) {
+	function normalizeUrl(url: string) {
+		return url[url.length - 1] === '/' ? url.substr(0, url.length - 1) : url;
 	}
 
-	app.get('/disconnect/twitter', async (req, res): Promise<any> => {
-		if (!compareOrigin(req)) {
-			res.status(400).send('invalid origin');
-			return;
-		}
+	const referer = ctx.headers['referer'];
 
-		const userToken = getUserToken(req);
-		if (userToken == null) return res.send('plz signin');
+	return (normalizeUrl(referer) == normalizeUrl(config.url));
+}
 
-		const user = await User.findOneAndUpdate({
-			host: null,
-			'token': userToken
-		}, {
-			$set: {
-				'twitter': null
-			}
-		});
+// Init router
+const router = new Router();
+
+router.get('/disconnect/twitter', async ctx => {
+	if (!compareOrigin(ctx)) {
+		ctx.throw(400, 'invalid origin');
+		return;
+	}
 
-		res.send(`Twitterの連携を解除しました :v:`);
+	const userToken = getUserToken(ctx);
+	if (userToken == null) {
+		ctx.throw(400, 'signin required');
+		return;
+	}
 
-		// Publish i updated event
-		event(user._id, 'i_updated', await pack(user, user, {
-			detail: true,
-			includeSecrets: true
-		}));
+	const user = await User.findOneAndUpdate({
+		host: null,
+		'token': userToken
+	}, {
+		$set: {
+			'twitter': null
+		}
 	});
 
-	if (config.twitter == null) {
-		app.get('/connect/twitter', (req, res) => {
-			res.send('現在Twitterへ接続できません (このインスタンスではTwitterはサポートされていません)');
-		});
+	ctx.body = `Twitterの連携を解除しました :v:`;
 
-		app.get('/signin/twitter', (req, res) => {
-			res.send('現在Twitterへ接続できません (このインスタンスではTwitterはサポートされていません)');
-		});
+	// Publish i updated event
+	event(user._id, 'i_updated', await pack(user, user, {
+		detail: true,
+		includeSecrets: true
+	}));
+});
 
-		return;
-	}
+if (config.twitter == null) {
+	router.get('/connect/twitter', ctx => {
+		ctx.body = '現在Twitterへ接続できません (このインスタンスではTwitterはサポートされていません)';
+	});
 
+	router.get('/signin/twitter', ctx => {
+		ctx.body = '現在Twitterへ接続できません (このインスタンスではTwitterはサポートされていません)';
+	});
+} else {
 	const twAuth = autwh({
 		consumerKey: config.twitter.consumer_key,
 		consumerSecret: config.twitter.consumer_secret,
 		callbackUrl: `${config.url}/api/tw/cb`
 	});
 
-	app.get('/connect/twitter', async (req, res): Promise<any> => {
-		if (!compareOrigin(req)) {
-			res.status(400).send('invalid origin');
+	router.get('/connect/twitter', async ctx => {
+		if (!compareOrigin(ctx)) {
+			ctx.throw(400, 'invalid origin');
 			return;
 		}
 
-		const userToken = getUserToken(req);
-		if (userToken == null) return res.send('plz signin');
+		const userToken = getUserToken(ctx);
+		if (userToken == null) {
+			ctx.throw(400, 'signin required');
+			return;
+		}
 
-		const ctx = await twAuth.begin();
-		redis.set(userToken, JSON.stringify(ctx));
-		res.redirect(ctx.url);
+		const twCtx = await twAuth.begin();
+		redis.set(userToken, JSON.stringify(twCtx));
+		ctx.redirect(twCtx.url);
 	});
 
-	app.get('/signin/twitter', async (req, res): Promise<any> => {
-		const ctx = await twAuth.begin();
+	router.get('/signin/twitter', async ctx => {
+		const twCtx = await twAuth.begin();
 
 		const sessid = uuid();
 
-		redis.set(sessid, JSON.stringify(ctx));
+		redis.set(sessid, JSON.stringify(twCtx));
 
 		const expires = 1000 * 60 * 60; // 1h
-		res.cookie('signin_with_twitter_session_id', sessid, {
+		ctx.cookies.set('signin_with_twitter_session_id', sessid, {
 			path: '/',
-			domain: `.${config.host}`,
-			secure: config.url.substr(0, 5) === 'https',
+			domain: config.host,
+			secure: config.url.startsWith('https'),
 			httpOnly: true,
 			expires: new Date(Date.now() + expires),
 			maxAge: expires
 		});
 
-		res.redirect(ctx.url);
+		ctx.redirect(twCtx.url);
 	});
 
-	app.get('/tw/cb', (req, res): any => {
-		const userToken = getUserToken(req);
+	router.get('/tw/cb', ctx => {
+		const userToken = getUserToken(ctx);
 
 		if (userToken == null) {
-			// req.headers['cookie'] は常に string ですが、型定義の都合上
-			// string | string[] になっているので string を明示しています
-			const cookies = cookie.parse((req.headers['cookie'] as string || ''));
+			const sessid = ctx.cookies.get('signin_with_twitter_session_id');
 
-			const sessid = cookies['signin_with_twitter_session_id'];
-
-			if (sessid == undefined) {
-				res.status(400).send('invalid session');
+			if (sessid == null) {
+				ctx.throw(400, 'invalid session');
 				return;
 			}
 
-			redis.get(sessid, async (_, ctx) => {
-				const result = await twAuth.done(JSON.parse(ctx), req.query.oauth_verifier);
+			redis.get(sessid, async (_, twCtx) => {
+				const result = await twAuth.done(JSON.parse(twCtx), ctx.query.oauth_verifier);
 
 				const user = await User.findOne({
 					host: null,
 					'twitter.userId': result.userId
-				});
+				}) as ILocalUser;
 
 				if (user == null) {
-					res.status(404).send(`@${result.screenName}と連携しているMisskeyアカウントはありませんでした...`);
+					ctx.throw(404, `@${result.screenName}と連携しているMisskeyアカウントはありませんでした...`);
 					return;
 				}
 
-				signin(res, user, true);
+				signin(ctx, user, true);
 			});
 		} else {
-			const verifier = req.query.oauth_verifier;
+			const verifier = ctx.query.oauth_verifier;
 
 			if (verifier == null) {
-				res.status(400).send('invalid session');
+				ctx.throw(400, 'invalid session');
 				return;
 			}
 
-			redis.get(userToken, async (_, ctx) => {
-				const result = await twAuth.done(JSON.parse(ctx), verifier);
+			redis.get(userToken, async (_, twCtx) => {
+				const result = await twAuth.done(JSON.parse(twCtx), verifier);
 
 				const user = await User.findOneAndUpdate({
 					host: null,
-					'token': userToken
+					token: userToken
 				}, {
 					$set: {
-						'twitter': {
+						twitter: {
 							accessToken: result.accessToken,
 							accessTokenSecret: result.accessTokenSecret,
 							userId: result.userId,
@@ -163,7 +158,7 @@ module.exports = (app: express.Application) => {
 					}
 				});
 
-				res.send(`Twitter: @${result.screenName} を、Misskey: @${user.username} に接続しました！`);
+				ctx.body = `Twitter: @${result.screenName} を、Misskey: @${user.username} に接続しました！`;
 
 				// Publish i updated event
 				event(user._id, 'i_updated', await pack(user, user, {
@@ -173,4 +168,6 @@ module.exports = (app: express.Application) => {
 			});
 		}
 	});
-};
+}
+
+module.exports = router;
diff --git a/src/server/file/index.ts b/src/server/file/index.ts
index 658117e3acb5000d6466055db070f8e92b3d513f..d305286d125577addc944faefc0a9434f5563831 100644
--- a/src/server/file/index.ts
+++ b/src/server/file/index.ts
@@ -3,170 +3,38 @@
  */
 
 import * as fs from 'fs';
-import * as express from 'express';
-import * as bodyParser from 'body-parser';
-import * as cors from 'cors';
-import * as mongodb from 'mongodb';
-import * as _gm from 'gm';
-import * as stream from 'stream';
-
-import DriveFile, { getGridFSBucket } from '../../models/drive-file';
-
-const gm = _gm.subClass({
-	imageMagick: true
-});
-
-/**
- * Init app
- */
-const app = express();
-
-app.disable('x-powered-by');
-app.locals.cache = true;
-app.use(bodyParser.urlencoded({ extended: true }));
+import * as Koa from 'koa';
+import * as cors from '@koa/cors';
+import * as Router from 'koa-router';
+import pour from './pour';
+import sendDriveFile from './send-drive-file';
+
+// Init app
+const app = new Koa();
 app.use(cors());
 
-/**
- * Statics
- */
-app.use('/assets', express.static(`${__dirname}/assets`, {
-	maxAge: 1000 * 60 * 60 * 24 * 365 // 一年
-}));
-
-app.get('/', (req, res) => {
-	res.send('yee haw');
+app.use(async (ctx, next) => {
+	ctx.set('Cache-Control', 'max-age=31536000, immutable');
+	await next();
 });
 
-app.get('/default-avatar.jpg', (req, res) => {
+// Init router
+const router = new Router();
+
+router.get('/default-avatar.jpg', ctx => {
 	const file = fs.createReadStream(`${__dirname}/assets/avatar.jpg`);
-	send(file, 'image/jpeg', req, res);
+	pour(file, 'image/jpeg', ctx);
 });
 
-app.get('/app-default.jpg', (req, res) => {
+router.get('/app-default.jpg', ctx => {
 	const file = fs.createReadStream(`${__dirname}/assets/dummy.png`);
-	send(file, 'image/png', req, res);
+	pour(file, 'image/png', ctx);
 });
 
-interface ISend {
-	contentType: string;
-	stream: stream.Readable;
-}
-
-function thumbnail(data: stream.Readable, type: string, resize: number): ISend {
-	const readable: stream.Readable = (() => {
-		// 動画であれば
-		if (/^video\/.*$/.test(type)) {
-			// 実装は先延ばし
-			// 使わないことになったストリームはしっかり取り壊す
-			data.destroy();
-			return fs.createReadStream(`${__dirname}/assets/thumbnail-not-available.png`);
-		// 画像であれば
-		} else if (/^image\/.*$/.test(type) || type == 'application/xml') {
-			// 0フレーム目を送る
-			try {
-				return gm(data).selectFrame(0).stream();
-			// だめだったら
-			} catch (e) {
-				// 使わないことになったストリームはしっかり取り壊す
-				data.destroy();
-				return fs.createReadStream(`${__dirname}/assets/thumbnail-not-available.png`);
-			}
-		// 動画か画像以外
-		} else {
-			data.destroy();
-			return fs.createReadStream(`${__dirname}/assets/not-an-image.png`);
-		}
-	})();
-
-	let g = gm(readable);
-
-	if (resize) {
-		g = g.resize(resize, resize);
-	}
-
-	const stream = g
-		.compress('jpeg')
-		.quality(80)
-		.interlace('line')
-		.stream();
-
-	return {
-		contentType: 'image/jpeg',
-		stream
-	};
-}
-
-const commonReadableHandlerGenerator = (req: express.Request, res: express.Response) => (e: Error): void => {
-	console.dir(e);
-	req.destroy();
-	res.destroy(e);
-};
-
-function send(readable: stream.Readable, type: string, req: express.Request, res: express.Response): void {
-	readable.on('error', commonReadableHandlerGenerator(req, res));
-
-	const data = ((): ISend => {
-		if (req.query.thumbnail !== undefined) {
-			return thumbnail(readable, type, req.query.size);
-		}
-		return {
-			contentType: type,
-			stream: readable
-		};
-	})();
-
-	if (readable !== data.stream) {
-		data.stream.on('error', commonReadableHandlerGenerator(req, res));
-	}
-
-	if (req.query.download !== undefined) {
-		res.header('Content-Disposition', 'attachment');
-	}
-
-	res.header('Content-Type', data.contentType);
-
-	data.stream.pipe(res);
-
-	data.stream.on('end', () => {
-		res.end();
-	});
-}
-
-async function sendFileById(req: express.Request, res: express.Response): Promise<void> {
-	// Validate id
-	if (!mongodb.ObjectID.isValid(req.params.id)) {
-		res.status(400).send('incorrect id');
-		return;
-	}
-
-	const fileId = new mongodb.ObjectID(req.params.id);
-
-	// Fetch (drive) file
-	const file = await DriveFile.findOne({ _id: fileId });
-
-	// validate name
-	if (req.params.name !== undefined && req.params.name !== file.filename) {
-		res.status(404).send('there is no file has given name');
-		return;
-	}
-
-	if (file == null) {
-		res.status(404).sendFile(`${__dirname}/assets/dummy.png`);
-		return;
-	}
-
-	const bucket = await getGridFSBucket();
-
-	const readable = bucket.openDownloadStream(fileId);
-
-	send(readable, file.contentType, req, res);
-}
-
-/**
- * Routing
- */
+router.get('/:id', sendDriveFile);
+router.get('/:id/*', sendDriveFile);
 
-app.get('/:id', sendFileById);
-app.get('/:id/:name', sendFileById);
+// Register router
+app.use(router.routes());
 
 module.exports = app;
diff --git a/src/server/file/pour.ts b/src/server/file/pour.ts
new file mode 100644
index 0000000000000000000000000000000000000000..0fd0ad0e60fb98a604318fcc5677dbfdb07fd8df
--- /dev/null
+++ b/src/server/file/pour.ts
@@ -0,0 +1,88 @@
+import * as fs from 'fs';
+import * as stream from 'stream';
+import * as Koa from 'koa';
+import * as Gm from 'gm';
+
+const gm = Gm.subClass({
+	imageMagick: true
+});
+
+interface ISend {
+	contentType: string;
+	stream: stream.Readable;
+}
+
+function thumbnail(data: stream.Readable, type: string, resize: number): ISend {
+	const readable: stream.Readable = (() => {
+		// 動画であれば
+		if (/^video\/.*$/.test(type)) {
+			// TODO
+			// 使わないことになったストリームはしっかり取り壊す
+			data.destroy();
+			return fs.createReadStream(`${__dirname}/assets/thumbnail-not-available.png`);
+		// 画像であれば
+		// Note: SVGはapplication/xml
+		} else if (/^image\/.*$/.test(type) || type == 'application/xml') {
+			// 0フレーム目を送る
+			try {
+				return gm(data).selectFrame(0).stream();
+			// だめだったら
+			} catch (e) {
+				// 使わないことになったストリームはしっかり取り壊す
+				data.destroy();
+				return fs.createReadStream(`${__dirname}/assets/thumbnail-not-available.png`);
+			}
+		// 動画か画像以外
+		} else {
+			data.destroy();
+			return fs.createReadStream(`${__dirname}/assets/not-an-image.png`);
+		}
+	})();
+
+	let g = gm(readable);
+
+	if (resize) {
+		g = g.resize(resize, resize);
+	}
+
+	const stream = g
+		.compress('jpeg')
+		.quality(80)
+		.interlace('line')
+		.stream();
+
+	return {
+		contentType: 'image/jpeg',
+		stream
+	};
+}
+
+const commonReadableHandlerGenerator = (ctx: Koa.Context) => (e: Error): void => {
+	console.error(e);
+	ctx.status = 500;
+};
+
+export default function(readable: stream.Readable, type: string, ctx: Koa.Context): void {
+	readable.on('error', commonReadableHandlerGenerator(ctx));
+
+	const data = ((): ISend => {
+		if (ctx.query.thumbnail !== undefined) {
+			return thumbnail(readable, type, ctx.query.size);
+		}
+		return {
+			contentType: type,
+			stream: readable
+		};
+	})();
+
+	if (readable !== data.stream) {
+		data.stream.on('error', commonReadableHandlerGenerator(ctx));
+	}
+
+	if (ctx.query.download !== undefined) {
+		ctx.set('Content-Disposition', 'attachment');
+	}
+
+	ctx.set('Content-Type', data.contentType);
+	ctx.body = data.stream;
+}
diff --git a/src/server/file/send-drive-file.ts b/src/server/file/send-drive-file.ts
new file mode 100644
index 0000000000000000000000000000000000000000..e6ee19ff1d985b96b45323a03451f9a25c04331e
--- /dev/null
+++ b/src/server/file/send-drive-file.ts
@@ -0,0 +1,30 @@
+import * as Koa from 'koa';
+import * as send from 'koa-send';
+import * as mongodb from 'mongodb';
+import DriveFile, { getGridFSBucket } from '../../models/drive-file';
+import pour from './pour';
+
+export default async function(ctx: Koa.Context) {
+	// Validate id
+	if (!mongodb.ObjectID.isValid(ctx.params.id)) {
+		ctx.throw(400, 'incorrect id');
+		return;
+	}
+
+	const fileId = new mongodb.ObjectID(ctx.params.id);
+
+	// Fetch drive file
+	const file = await DriveFile.findOne({ _id: fileId });
+
+	if (file == null) {
+		ctx.status = 404;
+		await send(ctx, `${__dirname}/assets/dummy.png`);
+		return;
+	}
+
+	const bucket = await getGridFSBucket();
+
+	const readable = bucket.openDownloadStream(fileId);
+
+	pour(readable, file.contentType, ctx);
+}
diff --git a/src/server/index.ts b/src/server/index.ts
index abb8992da5958f7edbdc65400bce7d4055fe925d..db41a1dcb5c738681e7b72e0eee43339ea4fa92d 100644
--- a/src/server/index.ts
+++ b/src/server/index.ts
@@ -4,68 +4,48 @@
 
 import * as fs from 'fs';
 import * as http from 'http';
-import * as https from 'https';
-import * as express from 'express';
-import * as morgan from 'morgan';
-import Accesses from 'accesses';
+import * as http2 from 'http2';
+import * as zlib from 'zlib';
+import * as Koa from 'koa';
+import * as Router from 'koa-router';
+import * as mount from 'koa-mount';
+import * as compress from 'koa-compress';
 
 import activityPub from './activitypub';
 import webFinger from './webfinger';
-import log from './log-request';
 import config from '../config';
 
-/**
- * Init app
- */
-const app = express();
-app.disable('x-powered-by');
-app.set('trust proxy', 'loopback');
+// Init app
+const app = new Koa();
+app.proxy = true;
 
-// Log
-if (config.accesses && config.accesses.enable) {
-	const accesses = new Accesses({
-		appName: 'Misskey',
-		port: config.accesses.port
-	});
+app.use(compress({
+	flush: zlib.constants.Z_SYNC_FLUSH
+}));
 
-	app.use(accesses.express);
+// HSTS
+// 6months (15552000sec)
+if (config.url.startsWith('https')) {
+	app.use(async (ctx, next) => {
+		ctx.set('strict-transport-security', 'max-age=15552000; preload');
+		await next();
+	});
 }
 
-app.use(morgan(process.env.NODE_ENV == 'production' ? 'combined' : 'dev', {
-	// create a write stream (in append mode)
-	stream: config.accesslog ? fs.createWriteStream(config.accesslog) : null
-}));
+app.use(mount('/api', require('./api')));
+app.use(mount('/files', require('./file')));
 
-app.use((req, res, next) => {
-	log(req);
-	next();
-});
+// Init router
+const router = new Router();
 
-// Drop request when without 'Host' header
-app.use((req, res, next) => {
-	if (!req.headers['host']) {
-		res.sendStatus(400);
-	} else {
-		next();
-	}
-});
+// Routing
+router.use(activityPub.routes());
+router.use(webFinger.routes());
 
-// 互換性のため
-app.post('/meta', (req, res) => {
-	res.header('Access-Control-Allow-Origin', '*');
-	res.json({
-		version: 'nighthike'
-	});
-});
+// Register router
+app.use(router.routes());
 
-/**
- * Register modules
- */
-app.use('/api', require('./api'));
-app.use('/files', require('./file'));
-app.use(activityPub);
-app.use(webFinger);
-app.use(require('./web'));
+app.use(mount(require('./web')));
 
 function createServer() {
 	if (config.https) {
@@ -73,9 +53,9 @@ function createServer() {
 		Object.keys(config.https).forEach(k => {
 			certs[k] = fs.readFileSync(config.https[k]);
 		});
-		return https.createServer(certs, app);
+		return http2.createSecureServer(certs, app.callback());
 	} else {
-		return http.createServer(app);
+		return http.createServer(app.callback());
 	}
 }
 
diff --git a/src/server/log-request.ts b/src/server/log-request.ts
deleted file mode 100644
index e431aa271d7ea4e40fd29ea7723c7f8c1e08a130..0000000000000000000000000000000000000000
--- a/src/server/log-request.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-import * as crypto from 'crypto';
-import * as express from 'express';
-import * as proxyAddr from 'proxy-addr';
-import Xev from 'xev';
-
-const ev = new Xev();
-
-export default function(req: express.Request) {
-	const ip = proxyAddr(req, () => true);
-
-	const md5 = crypto.createHash('md5');
-	md5.update(ip);
-	const hashedIp = md5.digest('hex').substr(0, 3);
-
-	ev.emit('request', {
-		ip: hashedIp,
-		method: req.method,
-		hostname: req.hostname,
-		path: req.originalUrl
-	});
-}
diff --git a/src/server/web/docs.ts b/src/server/web/docs.ts
index 889532e17e4c438cdff1deaf1640b4f95cff00fc..e65cc87b12691b03f178829de1226014f27fc97e 100644
--- a/src/server/web/docs.ts
+++ b/src/server/web/docs.ts
@@ -1,24 +1,27 @@
 /**
- * Docs Server
+ * Docs
  */
 
-import * as path from 'path';
-import * as express from 'express';
+import ms = require('ms');
+import * as Router from 'koa-router';
+import * as send from 'koa-send';
 
-const docs = path.resolve(`${__dirname}/../../client/docs/`);
+const docs = `${__dirname}/../../client/docs/`;
 
-/**
- * Init app
- */
-const app = express();
-app.disable('x-powered-by');
+const router = new Router();
 
-app.use('/assets', express.static(`${docs}/assets`));
+router.get('/assets/*', async ctx => {
+	await send(ctx, ctx.params[0], {
+		root: docs + '/assets/',
+		maxage: ms('7 days'),
+		immutable: true
+	});
+});
 
-/**
- * Routing
- */
-app.get(/^\/([a-z_\-\/]+?)$/, (req, res) =>
-	res.sendFile(`${docs}/${req.params[0]}.html`));
+router.get('*', async ctx => {
+	await send(ctx, `${ctx.params[0]}.html`, {
+		root: docs
+	});
+});
 
-module.exports = app;
+export default router;
diff --git a/src/server/web/index.ts b/src/server/web/index.ts
index 5b1b6409b9b7d0cfc1a5fb1f2a6707ca055ba1eb..376aadda730432f33cfff2c2ca582ef50faf2a91 100644
--- a/src/server/web/index.ts
+++ b/src/server/web/index.ts
@@ -2,63 +2,75 @@
  * Web Client Server
  */
 
-import * as path from 'path';
 import ms = require('ms');
+import * as Koa from 'koa';
+import * as Router from 'koa-router';
+import * as send from 'koa-send';
+import * as favicon from 'koa-favicon';
 
-// express modules
-import * as express from 'express';
-import * as bodyParser from 'body-parser';
-import * as favicon from 'serve-favicon';
-import * as compression from 'compression';
+import docs from './docs';
 
-const client = path.resolve(`${__dirname}/../../client/`);
+const client = `${__dirname}/../../client/`;
 
-// Create server
-const app = express();
-app.disable('x-powered-by');
+// Init app
+const app = new Koa();
 
-app.use('/docs', require('./docs'));
-
-app.use(bodyParser.urlencoded({ extended: true }));
-app.use(bodyParser.json({
-	type: ['application/json', 'text/plain']
-}));
-app.use(compression());
+// Serve favicon
+app.use(favicon(`${client}/assets/favicon.ico`));
 
-app.use((req, res, next) => {
-	res.header('X-Frame-Options', 'DENY');
-	next();
+// Common request handler
+app.use(async (ctx, next) => {
+	// IFrameの中に入れられないようにする
+	ctx.set('X-Frame-Options', 'DENY');
+	await next();
 });
 
+// Init router
+const router = new Router();
+
 //#region static assets
 
-app.use(favicon(`${client}/assets/favicon.ico`));
-app.get('/apple-touch-icon.png', (req, res) => res.sendFile(`${client}/assets/apple-touch-icon.png`));
-app.use('/assets', express.static(`${client}/assets`, {
-	maxAge: ms('7 days')
-}));
-app.use('/assets/*.js', (req, res) => res.sendFile(`${client}/assets/404.js`));
-app.use('/assets', (req, res) => {
-	res.sendStatus(404);
+router.get('/assets/*', async ctx => {
+	await send(ctx, ctx.path, {
+		root: client,
+		maxage: ms('7 days'),
+		immutable: true
+	});
+});
+
+// Apple touch icon
+router.get('/apple-touch-icon.png', async ctx => {
+	await send(ctx, `${client}/assets/apple-touch-icon.png`);
 });
 
 // ServiceWroker
-app.get(/^\/sw\.(.+?)\.js$/, (req, res) =>
-	res.sendFile(`${client}/assets/sw.${req.params[0]}.js`));
+router.get(/^\/sw\.(.+?)\.js$/, async ctx => {
+	await send(ctx, `${client}/assets/sw.${ctx.params[0]}.js`);
+});
 
 // Manifest
-app.get('/manifest.json', (req, res) =>
-	res.sendFile(`${client}/assets/manifest.json`));
+router.get('/manifest.json', async ctx => {
+	await send(ctx, `${client}/assets/manifest.json`);
+});
 
 //#endregion
 
-app.get(/\/api:url/, require('./url-preview'));
+// Docs
+router.use('/docs', docs.routes());
+
+// URL preview endpoint
+router.get('url', require('./url-preview'));
 
 // Render base html for all requests
-app.get('*', (req, res) => {
-	res.sendFile(path.resolve(`${client}/app/base.html`), {
-		maxAge: ms('7 days')
+router.get('*', async ctx => {
+	await send(ctx, `app/base.html`, {
+		root: client,
+		maxage: ms('3 days'),
+		immutable: true
 	});
 });
 
+// Register router
+app.use(router.routes());
+
 module.exports = app;
diff --git a/src/server/web/url-preview.ts b/src/server/web/url-preview.ts
index 0c5fd8a78e77a7ef4ecf6bda8897d00414ab4fa4..4b3f44a5da9804088254266a34a11680560ddd26 100644
--- a/src/server/web/url-preview.ts
+++ b/src/server/web/url-preview.ts
@@ -1,11 +1,11 @@
-import * as express from 'express';
+import * as Koa from 'koa';
 import summaly from 'summaly';
 
-module.exports = async (req: express.Request, res: express.Response) => {
-	const summary = await summaly(req.query.url);
+module.exports = async (ctx: Koa.Context) => {
+	const summary = await summaly(ctx.query.url);
 	summary.icon = wrap(summary.icon);
 	summary.thumbnail = wrap(summary.thumbnail);
-	res.send(summary);
+	ctx.body = summary;
 };
 
 function wrap(url: string): string {
diff --git a/src/server/webfinger.ts b/src/server/webfinger.ts
index dbf0999f3e3afcfe1978ace0de4361e7bd6e2909..e72592351bcaa7d3d86c7b861322788b1a148747 100644
--- a/src/server/webfinger.ts
+++ b/src/server/webfinger.ts
@@ -1,17 +1,19 @@
-import * as express from 'express';
+import * as Router from 'koa-router';
 
 import config from '../config';
 import parseAcct from '../acct/parse';
 import User from '../models/user';
 
-const app = express.Router();
+// Init router
+const router = new Router();
 
-app.get('/.well-known/webfinger', async (req, res) => {
-	if (typeof req.query.resource !== 'string') {
-		return res.sendStatus(400);
+router.get('/.well-known/webfinger', async ctx => {
+	if (typeof ctx.query.resource !== 'string') {
+		ctx.status = 400;
+		return;
 	}
 
-	const resourceLower = req.query.resource.toLowerCase();
+	const resourceLower = ctx.query.resource.toLowerCase();
 	const webPrefix = config.url.toLowerCase() + '/@';
 	let acctLower;
 
@@ -25,15 +27,21 @@ app.get('/.well-known/webfinger', async (req, res) => {
 
 	const parsedAcctLower = parseAcct(acctLower);
 	if (![null, config.host.toLowerCase()].includes(parsedAcctLower.host)) {
-		return res.sendStatus(422);
+		ctx.status = 422;
+		return;
 	}
 
-	const user = await User.findOne({ usernameLower: parsedAcctLower.username, host: null });
+	const user = await User.findOne({
+		usernameLower: parsedAcctLower.username,
+		host: null
+	});
+
 	if (user === null) {
-		return res.sendStatus(404);
+		ctx.status = 404;
+		return;
 	}
 
-	return res.json({
+	ctx.body = {
 		subject: `acct:${user.username}@${config.host}`,
 		links: [{
 			rel: 'self',
@@ -47,7 +55,7 @@ app.get('/.well-known/webfinger', async (req, res) => {
 			rel: 'http://ostatus.org/schema/1.0/subscribe',
 			template: `${config.url}/authorize-follow?acct={uri}`
 		}]
-	});
+	};
 });
 
-export default app;
+export default router;
diff --git a/src/services/following/create.ts b/src/services/following/create.ts
index 31e3be19ed84a1fd61b9deae34a1e37dae5814b9..3289e31294a8e4cf48e9a7f56de3cbe2e118eef0 100644
--- a/src/services/following/create.ts
+++ b/src/services/following/create.ts
@@ -4,7 +4,7 @@ import FollowingLog from '../../models/following-log';
 import FollowedLog from '../../models/followed-log';
 import event from '../../publishers/stream';
 import notify from '../../publishers/notify';
-import context from '../../remote/activitypub/renderer/context';
+import pack from '../../remote/activitypub/renderer';
 import renderFollow from '../../remote/activitypub/renderer/follow';
 import renderAccept from '../../remote/activitypub/renderer/accept';
 import { deliver } from '../../queue';
@@ -57,16 +57,12 @@ export default async function(follower: IUser, followee: IUser, activity?) {
 	}
 
 	if (isLocalUser(follower) && isRemoteUser(followee)) {
-		const content = renderFollow(follower, followee);
-		content['@context'] = context;
-
+		const content = pack(renderFollow(follower, followee));
 		deliver(follower, content, followee.inbox).save();
 	}
 
 	if (isRemoteUser(follower) && isLocalUser(followee)) {
-		const content = renderAccept(activity);
-		content['@context'] = context;
-
+		const content = pack(renderAccept(activity));
 		deliver(followee, content, follower.inbox).save();
 	}
 }
diff --git a/src/services/following/delete.ts b/src/services/following/delete.ts
index d79bf64f5329bde5a1bc3f767e644faf0d9da07e..8b6c56816a3d9799ae8dca3e246800406f591b92 100644
--- a/src/services/following/delete.ts
+++ b/src/services/following/delete.ts
@@ -3,7 +3,7 @@ import Following from '../../models/following';
 import FollowingLog from '../../models/following-log';
 import FollowedLog from '../../models/followed-log';
 import event from '../../publishers/stream';
-import context from '../../remote/activitypub/renderer/context';
+import pack from '../../remote/activitypub/renderer';
 import renderFollow from '../../remote/activitypub/renderer/follow';
 import renderUndo from '../../remote/activitypub/renderer/undo';
 import { deliver } from '../../queue';
@@ -56,9 +56,7 @@ export default async function(follower: IUser, followee: IUser, activity?) {
 	}
 
 	if (isLocalUser(follower) && isRemoteUser(followee)) {
-		const content = renderUndo(renderFollow(follower, followee));
-		content['@context'] = context;
-
+		const content = pack(renderUndo(renderFollow(follower, followee)));
 		deliver(follower, content, followee.inbox).save();
 	}
 }
diff --git a/src/services/note/create.ts b/src/services/note/create.ts
index 8f0b84bccd9a632bb4e2c83e3db16e8618071a19..b238cd560729858c1482557abc9e90e7f5880e6e 100644
--- a/src/services/note/create.ts
+++ b/src/services/note/create.ts
@@ -6,7 +6,7 @@ import { deliver } from '../../queue';
 import renderNote from '../../remote/activitypub/renderer/note';
 import renderCreate from '../../remote/activitypub/renderer/create';
 import renderAnnounce from '../../remote/activitypub/renderer/announce';
-import context from '../../remote/activitypub/renderer/context';
+import packAp from '../../remote/activitypub/renderer';
 import { IDriveFile } from '../../models/drive-file';
 import notify from '../../publishers/notify';
 import NoteWatching from '../../models/note-watching';
@@ -132,8 +132,7 @@ export default async (user: IUser, data: {
 				const content = data.renote && data.text == null
 					? renderAnnounce(data.renote.uri ? data.renote.uri : await renderNote(data.renote))
 					: renderCreate(await renderNote(note));
-				content['@context'] = context;
-				return content;
+				return packAp(content);
 			};
 
 			// 投稿がリプライかつ投稿者がローカルユーザーかつリプライ先の投稿の投稿者がリモートユーザーなら配送
diff --git a/src/services/note/reaction/create.ts b/src/services/note/reaction/create.ts
index 88158034f3ed423893df685e12ae34347bf3e11a..69a14248da3260a517e34b677191433d50ae2c9c 100644
--- a/src/services/note/reaction/create.ts
+++ b/src/services/note/reaction/create.ts
@@ -8,7 +8,7 @@ import NoteWatching from '../../../models/note-watching';
 import watch from '../watch';
 import renderLike from '../../../remote/activitypub/renderer/like';
 import { deliver } from '../../../queue';
-import context from '../../../remote/activitypub/renderer/context';
+import pack from '../../../remote/activitypub/renderer';
 
 export default async (user: IUser, note: INote, reaction: string) => new Promise(async (res, rej) => {
 	// Myself
@@ -85,9 +85,7 @@ export default async (user: IUser, note: INote, reaction: string) => new Promise
 	//#region 配信
 	// リアクターがローカルユーザーかつリアクション対象がリモートユーザーの投稿なら配送
 	if (isLocalUser(user) && isRemoteUser(note._user)) {
-		const content = renderLike(user, note);
-		content['@context'] = context;
-
+		const content = pack(renderLike(user, note));
 		deliver(user, content, note._user.inbox).save();
 	}
 	//#endregion