diff --git a/src/api/common/add-file-to-drive.ts b/src/api/common/add-file-to-drive.ts
index f48f0cbcf5..376c470e93 100644
--- a/src/api/common/add-file-to-drive.ts
+++ b/src/api/common/add-file-to-drive.ts
@@ -154,6 +154,7 @@ export default (
 		comment: comment,
 		properties: properties
 	});
+	console.dir(file)
 
 	log(`drive file has been created ${file._id}`);
 
diff --git a/src/api/endpoints/drive.ts b/src/api/endpoints/drive.ts
index 41ad6301d7..b9c4e3e506 100644
--- a/src/api/endpoints/drive.ts
+++ b/src/api/endpoints/drive.ts
@@ -14,16 +14,16 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Calculate drive usage
 	const usage = ((await DriveFile
 		.aggregate([
-			{ $match: { user_id: user._id } },
+			{ $match: { metadata: { user_id: user._id } } },
 			{
 				$project: {
-					datasize: true
+					length: true
 				}
 			},
 			{
 				$group: {
 					_id: null,
-					usage: { $sum: '$datasize' }
+					usage: { $sum: '$length' }
 				}
 			}
 		]))[0] || {
diff --git a/src/api/endpoints/drive/files.ts b/src/api/endpoints/drive/files.ts
index a68ae34817..eb0bfe6ba5 100644
--- a/src/api/endpoints/drive/files.ts
+++ b/src/api/endpoints/drive/files.ts
@@ -40,8 +40,10 @@ module.exports = (params, user, app) => new Promise(async (res, rej) => {
 		_id: -1
 	};
 	const query = {
-		user_id: user._id,
-		folder_id: folderId
+		metadata: {
+			user_id: user._id,
+			folder_id: folderId
+		}
 	} as any;
 	if (sinceId) {
 		sort._id = 1;
@@ -57,9 +59,6 @@ module.exports = (params, user, app) => new Promise(async (res, rej) => {
 	// Issue query
 	const files = await DriveFile
 		.find(query, {
-			fields: {
-				data: false
-			},
 			limit: limit,
 			sort: sort
 		});
diff --git a/src/api/endpoints/drive/files/find.ts b/src/api/endpoints/drive/files/find.ts
index cd0b33f2ca..255faf94ec 100644
--- a/src/api/endpoints/drive/files/find.ts
+++ b/src/api/endpoints/drive/files/find.ts
@@ -24,12 +24,10 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Issue query
 	const files = await DriveFile
 		.find({
-			name: name,
-			user_id: user._id,
-			folder_id: folderId
-		}, {
-			fields: {
-				data: false
+			metadata: {
+				name: name,
+				user_id: user._id,
+				folder_id: folderId
 			}
 		});
 
diff --git a/src/api/endpoints/drive/files/show.ts b/src/api/endpoints/drive/files/show.ts
index 8dbc297e4f..9135a04c57 100644
--- a/src/api/endpoints/drive/files/show.ts
+++ b/src/api/endpoints/drive/files/show.ts
@@ -21,10 +21,8 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	const file = await DriveFile
 		.findOne({
 			_id: fileId,
-			user_id: user._id
-		}, {
-			fields: {
-				data: false
+			metadata: {
+				user_id: user._id
 			}
 		});
 
diff --git a/src/api/endpoints/drive/files/update.ts b/src/api/endpoints/drive/files/update.ts
index 1cfbdd8f0b..c4d2673688 100644
--- a/src/api/endpoints/drive/files/update.ts
+++ b/src/api/endpoints/drive/files/update.ts
@@ -20,25 +20,29 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	const [fileId, fileIdErr] = $(params.file_id).id().$;
 	if (fileIdErr) return rej('invalid file_id param');
 
+	console.dir(user)
+
 	// Fetch file
 	const file = await DriveFile
 		.findOne({
 			_id: fileId,
-			user_id: user._id
-		}, {
-			fields: {
-				data: false
+			metadata: {
+				user_id: user._id
 			}
 		});
 
+	console.dir(file)
+
 	if (file === null) {
 		return rej('file-not-found');
 	}
 
+	const updateQuery: any = {}
+
 	// Get 'name' parameter
 	const [name, nameErr] = $(params.name).optional.string().pipe(validateFileName).$;
 	if (nameErr) return rej('invalid name param');
-	if (name) file.name = name;
+	if (name) updateQuery.name = name;
 
 	// Get 'folder_id' parameter
 	const [folderId, folderIdErr] = $(params.folder_id).optional.nullable.id().$;
@@ -46,7 +50,7 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 
 	if (folderId !== undefined) {
 		if (folderId === null) {
-			file.folder_id = null;
+			updateQuery.folder_id = null;
 		} else {
 			// Fetch folder
 			const folder = await DriveFolder
@@ -59,19 +63,20 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 				return rej('folder-not-found');
 			}
 
-			file.folder_id = folder._id;
+			updateQuery.folder_id = folder._id;
 		}
 	}
 
-	DriveFile.update(file._id, {
-		$set: {
-			name: file.name,
-			folder_id: file.folder_id
-		}
+	const updated = await DriveFile.update(file._id, {
+		$set: { metadata: updateQuery }
 	});
 
+	console.dir(updated)
+
 	// Serialize
-	const fileObj = await serialize(file);
+	const fileObj = await serialize(updated);
+
+	console.dir(fileObj)
 
 	// Response
 	res(fileObj);
diff --git a/src/api/endpoints/messaging/messages/create.ts b/src/api/endpoints/messaging/messages/create.ts
index 8af55d850c..1d186268fb 100644
--- a/src/api/endpoints/messaging/messages/create.ts
+++ b/src/api/endpoints/messaging/messages/create.ts
@@ -54,9 +54,9 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	if (fileId !== undefined) {
 		file = await DriveFile.findOne({
 			_id: fileId,
-			user_id: user._id
-		}, {
-			data: false
+			metadata: {
+				user_id: user._id
+			}
 		});
 
 		if (file === null) {
diff --git a/src/api/endpoints/posts/create.ts b/src/api/endpoints/posts/create.ts
index f982b9ee93..1507639776 100644
--- a/src/api/endpoints/posts/create.ts
+++ b/src/api/endpoints/posts/create.ts
@@ -44,9 +44,9 @@ module.exports = (params, user: IUser, app) => new Promise(async (res, rej) => {
 			// SELECT _id
 			const entity = await DriveFile.findOne({
 				_id: mediaId,
-				user_id: user._id
-			}, {
-				_id: true
+				metadata: {
+					user_id: user._id
+				}
 			});
 
 			if (entity === null) {
diff --git a/src/api/endpoints/posts/timeline.ts b/src/api/endpoints/posts/timeline.ts
index aa5aff5ba5..496de62b69 100644
--- a/src/api/endpoints/posts/timeline.ts
+++ b/src/api/endpoints/posts/timeline.ts
@@ -2,6 +2,7 @@
  * Module dependencies
  */
 import $ from 'cafy';
+import rap from '@prezzemolo/rap';
 import Post from '../../models/post';
 import ChannelWatching from '../../models/channel-watching';
 import getFriends from '../../common/get-friends';
@@ -33,14 +34,15 @@ module.exports = (params, user, app) => new Promise(async (res, rej) => {
 		return rej('cannot set since_id and max_id');
 	}
 
-	// ID list of the user itself and other users who the user follows
-	const followingIds = await getFriends(user._id);
-
-	// Watchしているチャンネルを取得
-	const watches = await ChannelWatching.find({
-		user_id: user._id,
-		// 削除されたドキュメントは除く
-		deleted_at: { $exists: false }
+	const { followingIds, watchChannelIds } = await rap({
+		// ID list of the user itself and other users who the user follows
+		followingIds: getFriends(user._id),
+		// Watchしているチャンネルを取得
+		watchChannelIds: ChannelWatching.find({
+			user_id: user._id,
+			// 削除されたドキュメントは除く
+			deleted_at: { $exists: false }
+		}).then(watches => watches.map(w => w.channel_id))
 	});
 
 	//#region Construct query
@@ -65,7 +67,7 @@ module.exports = (params, user, app) => new Promise(async (res, rej) => {
 		}, {
 			// Watchしているチャンネルへの投稿
 			channel_id: {
-				$in: watches.map(w => w.channel_id)
+				$in: watchChannelIds
 			}
 		}]
 	} as any;
@@ -90,7 +92,5 @@ module.exports = (params, user, app) => new Promise(async (res, rej) => {
 		});
 
 	// Serialize
-	res(await Promise.all(timeline.map(async post =>
-		await serialize(post, user)
-	)));
+	res(Promise.all(timeline.map(post => serialize(post, user))));
 });
diff --git a/src/api/serializers/drive-file.ts b/src/api/serializers/drive-file.ts
index b4e2ab064a..4c750f4c6b 100644
--- a/src/api/serializers/drive-file.ts
+++ b/src/api/serializers/drive-file.ts
@@ -31,44 +31,37 @@ export default (
 	if (mongo.ObjectID.prototype.isPrototypeOf(file)) {
 		_file = await DriveFile.findOne({
 			_id: file
-		}, {
-				fields: {
-					data: false
-				}
-			});
+		});
 	} else if (typeof file === 'string') {
 		_file = await DriveFile.findOne({
 			_id: new mongo.ObjectID(file)
-		}, {
-				fields: {
-					data: false
-				}
-			});
+		});
 	} else {
 		_file = deepcopy(file);
 	}
 
-	// Rename _id to id
-	_file.id = _file._id;
-	delete _file._id;
+	// rendered target
+	let _target: any = {};
 
-	delete _file.data;
+	_target.id = _file._id;
 
-	_file.url = `${config.drive_url}/${_file.id}/${encodeURIComponent(_file.name)}`;
+	_target = Object.assign(_target, _file.metadata);
 
-	if (opts.detail && _file.folder_id) {
+	_target.url = `${config.drive_url}/${_target.id}/${encodeURIComponent(_target.name)}`;
+
+	if (opts.detail && _target.folder_id) {
 		// Populate folder
-		_file.folder = await serializeDriveFolder(_file.folder_id, {
+		_target.folder = await serializeDriveFolder(_target.folder_id, {
 			detail: true
 		});
 	}
 
-	if (opts.detail && _file.tags) {
+	if (opts.detail && _target.tags) {
 		// Populate tags
-		_file.tags = await _file.tags.map(async (tag: any) =>
+		_target.tags = await _target.tags.map(async (tag: any) =>
 			await serializeDriveTag(tag)
 		);
 	}
 
-	resolve(_file);
+	resolve(_target);
 });
diff --git a/src/api/serializers/drive-folder.ts b/src/api/serializers/drive-folder.ts
index a428464108..3b5f61aeed 100644
--- a/src/api/serializers/drive-folder.ts
+++ b/src/api/serializers/drive-folder.ts
@@ -44,7 +44,9 @@ const self = (
 		});
 
 		const childFilesCount = await DriveFile.count({
-			folder_id: _folder.id
+			metadata: {
+				folder_id: _folder.id
+			}
 		});
 
 		_folder.folders_count = childFoldersCount;