diff --git a/packages/backend/src/core/MahjongService.ts b/packages/backend/src/core/MahjongService.ts
index 1c36aea0c1..33449334db 100644
--- a/packages/backend/src/core/MahjongService.ts
+++ b/packages/backend/src/core/MahjongService.ts
@@ -77,6 +77,10 @@ type NextKyokuConfirmation = {
 	user4: boolean;
 };
 
+function getUserIdOfHouse(room: Room, engine: Mahjong.MasterGameEngine, house: Mahjong.Common.House): MiUser['id'] {
+	return engine.state.user1House === house ? room.user1Id : engine.state.user2House === house ? room.user2Id : engine.state.user3House === house ? room.user3Id : room.user4Id;
+}
+
 @Injectable()
 export class MahjongService implements OnApplicationShutdown, OnModuleInit {
 	private notificationService: NotificationService;
@@ -302,62 +306,71 @@ export class MahjongService implements OnApplicationShutdown, OnModuleInit {
 			pon: answers.pon ?? false,
 			cii: answers.cii ?? false,
 			kan: answers.kan ?? false,
-			ron: [...(answers.ron.e ? ['e'] : []), ...(answers.ron.s ? ['s'] : []), ...(answers.ron.w ? ['w'] : []), ...(answers.ron.n ? ['n'] : [])],
+			ron: [...(answers.ron.e ? ['e'] : []), ...(answers.ron.s ? ['s'] : []), ...(answers.ron.w ? ['w'] : []), ...(answers.ron.n ? ['n'] : [])] as Mahjong.Common.House[],
 		});
 		room.gameState = engine.state;
 		await this.saveRoom(room);
 
-		if (res.type === 'tsumo') {
-			this.globalEventService.publishMahjongRoomStream(room.id, 'tsumo', { house: res.house, tile: res.tile });
-			this.next(room, engine);
-		} else if (res.type === 'ponned') {
-			this.globalEventService.publishMahjongRoomStream(room.id, 'ponned', { caller: res.caller, callee: res.callee, tile: res.tile });
-			const userId = engine.state.user1House === engine.state.turn ? room.user1Id : engine.state.user2House === engine.state.turn ? room.user2Id : engine.state.user3House === engine.state.turn ? room.user3Id : room.user4Id;
-			this.waitForTurn(room, userId, engine);
-		} else if (res.type === 'kanned') {
-			this.globalEventService.publishMahjongRoomStream(room.id, 'kanned', { caller: res.caller, callee: res.callee, tile: res.tile, rinsyan: res.rinsyan });
-			const userId = engine.state.user1House === engine.state.turn ? room.user1Id : engine.state.user2House === engine.state.turn ? room.user2Id : engine.state.user3House === engine.state.turn ? room.user3Id : room.user4Id;
-			this.waitForTurn(room, userId, engine);
-		} else if (res.type === 'ronned') {
-			this.globalEventService.publishMahjongRoomStream(room.id, 'ronned', {
-				callers: res.callers,
-				callee: res.callee,
-				handTiles: {
-					e: engine.state.handTiles.e,
-					s: engine.state.handTiles.s,
-					w: engine.state.handTiles.w,
-					n: engine.state.handTiles.n,
-				},
-			});
-			this.endKyoku(room, engine);
+		switch (res.type) {
+			case 'tsumo':
+				this.globalEventService.publishMahjongRoomStream(room.id, 'tsumo', { house: res.house, tile: res.tile });
+				this.next(room, engine);
+				break;
+			case 'ponned':
+				this.globalEventService.publishMahjongRoomStream(room.id, 'ponned', { caller: res.caller, callee: res.callee, tile: res.tile });
+				this.waitForTurn(room, res.turn, engine);
+				break;
+			case 'kanned':
+				this.globalEventService.publishMahjongRoomStream(room.id, 'kanned', { caller: res.caller, callee: res.callee, tile: res.tile, rinsyan: res.rinsyan });
+				this.waitForTurn(room, res.turn, engine);
+				break;
+			case 'ronned':
+				this.globalEventService.publishMahjongRoomStream(room.id, 'ronned', {
+					callers: res.callers,
+					callee: res.callee,
+					handTiles: {
+						e: engine.state.handTiles.e,
+						s: engine.state.handTiles.s,
+						w: engine.state.handTiles.w,
+						n: engine.state.handTiles.n,
+					},
+				});
+				this.endKyoku(room, engine);
+				break;
+			case 'ryukyoku':
+				this.globalEventService.publishMahjongRoomStream(room.id, 'ryukyoku', {
+				});
+				this.endKyoku(room, engine);
+				break;
 		}
 	}
 
 	@bindThis
 	private async next(room: Room, engine: Mahjong.MasterGameEngine) {
-		const aiHouses = [[1, room.user1Ai], [2, room.user2Ai], [3, room.user3Ai], [4, room.user4Ai]].filter(([id, ai]) => ai).map(([id, ai]) => engine.getHouse(id));
-		const userId = engine.state.user1House === engine.state.turn ? room.user1Id : engine.state.user2House === engine.state.turn ? room.user2Id : engine.state.user3House === engine.state.turn ? room.user3Id : room.user4Id;
+		const turn = engine.state.turn;
+		if (turn == null) throw new Error('turn is null');
 
-		if (aiHouses.includes(engine.state.turn)) {
+		const aiHouses = [[1, room.user1Ai], [2, room.user2Ai], [3, room.user3Ai], [4, room.user4Ai]].filter(([id, ai]) => ai).map(([id, ai]) => engine.getHouse(id));
+
+		if (aiHouses.includes(turn)) {
 			// TODO: ちゃんと思考するようにする
 			setTimeout(() => {
-				const house = engine.state.turn;
-				this.dahai(room, engine, engine.state.turn, engine.state.handTiles[house].at(-1));
+				this.dahai(room, engine, turn, engine.state.handTiles[turn].at(-1));
 			}, 500);
 		} else {
-			if (engine.state.riichis[engine.state.turn]) {
+			if (engine.state.riichis[turn]) {
 				// リーチ時はアガリ牌でない限りツモ切り
-				const handTiles = engine.state.handTiles[engine.state.turn];
+				const handTiles = engine.state.handTiles[turn];
 				const horaSets = Mahjong.Utils.getHoraSets(handTiles);
 				if (horaSets.length === 0) {
 					setTimeout(() => {
-						this.dahai(room, engine, engine.state.turn, handTiles.at(-1));
+						this.dahai(room, engine, turn, handTiles.at(-1));
 					}, 500);
 				} else {
-					this.waitForTurn(room, userId, engine);
+					this.waitForTurn(room, turn, engine);
 				}
 			} else {
-				this.waitForTurn(room, userId, engine);
+				this.waitForTurn(room, turn, engine);
 			}
 		}
 	}
@@ -607,13 +620,13 @@ export class MahjongService implements OnApplicationShutdown, OnModuleInit {
 	 * 制限時間が過ぎたらツモ切り
 	 * NOTE: 時間切れチェックが行われたときにタイミングによっては次のwaitingが始まっている場合があることを考慮し、Setに一意のIDを格納する構造としている
 	 * @param room
-	 * @param userId
+	 * @param house
 	 * @param engine
 	 */
 	@bindThis
-	private async waitForTurn(room: Room, userId: MiUser['id'], engine: Mahjong.MasterGameEngine) {
+	private async waitForTurn(room: Room, house: Mahjong.Common.House, engine: Mahjong.MasterGameEngine) {
 		const id = Math.random().toString(36).slice(2);
-		console.log('waitForTurn', userId, id);
+		console.log('waitForTurn', house, id);
 		this.redisClient.sadd(`mahjong:gameTurnWaiting:${room.id}`, id);
 		const waitingStartedAt = Date.now();
 		const interval = setInterval(async () => {
@@ -624,9 +637,8 @@ export class MahjongService implements OnApplicationShutdown, OnModuleInit {
 			}
 			if (Date.now() - waitingStartedAt > TURN_TIMEOUT_MS) {
 				await this.redisClient.srem(`mahjong:gameTurnWaiting:${room.id}`, id);
-				console.log('turn timeout', userId, id);
+				console.log('turn timeout', house, id);
 				clearInterval(interval);
-				const house = room.user1Id === userId ? engine.state.user1House : room.user2Id === userId ? engine.state.user2House : room.user3Id === userId ? engine.state.user3House : engine.state.user4House;
 				const handTiles = engine.state.handTiles[house];
 				await this.dahai(room, engine, house, handTiles.at(-1));
 				return;
diff --git a/packages/misskey-mahjong/src/engine.master.ts b/packages/misskey-mahjong/src/engine.master.ts
index 7ca7f78828..20df90bac8 100644
--- a/packages/misskey-mahjong/src/engine.master.ts
+++ b/packages/misskey-mahjong/src/engine.master.ts
@@ -229,7 +229,7 @@ export class MasterGameEngine {
 				ronTile: this.state.hoTiles[callee].at(-1)!,
 				riichi: this.state.riichis[house],
 			}));
-			console.log('yakus', yakus);
+			console.log('yakus', house, yakus);
 		}
 
 		this.endKyoku();
@@ -330,7 +330,7 @@ export class MasterGameEngine {
 			this.state.turn = null;
 			this.state.nextTurnAfterAsking = Utils.nextHouse(house);
 			return {
-				asking: true,
+				asking: true as const,
 				canRonHouses: canRonHouses,
 				canKanHouse: canKanHouse,
 				canPonHouse: canPonHouse,
@@ -343,7 +343,7 @@ export class MasterGameEngine {
 		const tsumoTile = this.tsumo();
 
 		return {
-			asking: false,
+			asking: false as const,
 			tsumoTile: tsumoTile,
 		};
 	}
@@ -371,93 +371,91 @@ export class MasterGameEngine {
 	}) {
 		if (this.state.ponAsking == null && this.state.ciiAsking == null && this.state.kanAsking == null && this.state.ronAsking == null) throw new Error();
 
-		const clearAsking = () => {
-			this.state.ponAsking = null;
-			this.state.ciiAsking = null;
-			this.state.kanAsking = null;
-			this.state.ronAsking = null;
-		};
+		const pon = this.state.ponAsking;
+		const cii = this.state.ciiAsking;
+		const kan = this.state.kanAsking;
+		const ron = this.state.ronAsking;
 
-		if (this.state.ronAsking != null && answers.ron.length > 0) {
-			const callers = this.state.ronAsking.callers;
-			const callee = this.state.ronAsking.callee;
+		this.state.ponAsking = null;
+		this.state.ciiAsking = null;
+		this.state.kanAsking = null;
+		this.state.ronAsking = null;
 
-			this.ron(answers.ron, this.state.ronAsking.callee);
+		if (ron != null && answers.ron.length > 0) {
+			this.ron(answers.ron, ron.callee);
 			return {
-				type: 'ronned',
-				callers,
-				callee,
+				type: 'ronned' as const,
+				callers: ron.callers,
+				callee: ron.callee,
+				turn: null,
 			};
-		}
+		} else if (kan != null && answers.kan) {
+			// 大明槓
 
-		// 大明槓
-		if (this.state.kanAsking != null && answers.kan) {
-			const caller = this.state.kanAsking.caller;
-			const callee = this.state.kanAsking.callee;
-
-			const tile = this.state.hoTiles[callee].pop()!;
-			this.state.huros[caller].push({ type: 'minkan', tile, from: callee });
+			const tile = this.state.hoTiles[kan.callee].pop()!;
+			this.state.huros[kan.caller].push({ type: 'minkan', tile, from: kan.callee });
 
 			const rinsyan = this.tsumo();
 
-			clearAsking();
-			this.state.turn = caller;
+			this.state.turn = kan.caller;
 			return {
-				type: 'kanned',
-				caller,
-				callee,
+				type: 'kanned' as const,
+				caller: kan.caller,
+				callee: kan.callee,
 				tile,
 				rinsyan,
+				turn: this.state.turn,
 			};
-		}
+		} else if (pon != null && answers.pon) {
+			const tile = this.state.hoTiles[pon.callee].pop()!;
+			this.state.handTiles[pon.caller].splice(this.state.handTiles[pon.caller].indexOf(tile), 1);
+			this.state.handTiles[pon.caller].splice(this.state.handTiles[pon.caller].indexOf(tile), 1);
+			this.state.huros[pon.caller].push({ type: 'pon', tile, from: pon.callee });
 
-		if (this.state.ponAsking != null && answers.pon) {
-			const caller = this.state.ponAsking.caller;
-			const callee = this.state.ponAsking.callee;
-
-			const tile = this.state.hoTiles[callee].pop()!;
-			this.state.handTiles[caller].splice(this.state.handTiles[caller].indexOf(tile), 1);
-			this.state.handTiles[caller].splice(this.state.handTiles[caller].indexOf(tile), 1);
-			this.state.huros[caller].push({ type: 'pon', tile, from: callee });
-
-			clearAsking();
-			this.state.turn = caller;
+			this.state.turn = pon.caller;
 			return {
-				type: 'ponned',
-				caller,
-				callee,
+				type: 'ponned' as const,
+				caller: pon.caller,
+				callee: pon.callee,
 				tile,
+				turn: this.state.turn,
 			};
-		}
+		} else if (cii != null && answers.cii) {
+			const tile = this.state.hoTiles[cii.callee].pop()!;
+			this.state.huros[cii.caller].push({ type: 'cii', tile, from: cii.callee });
 
-		if (this.state.ciiAsking != null && answers.cii) {
-			const caller = this.state.ciiAsking.caller;
-			const callee = this.state.ciiAsking.callee;
-
-			const tile = this.state.hoTiles[callee].pop()!;
-			this.state.huros[caller].push({ type: 'cii', tile, from: callee });
-
-			clearAsking();
-			this.state.turn = caller;
+			this.state.turn = cii.caller;
 			return {
-				type: 'ciied',
-				caller,
-				callee,
+				type: 'ciied' as const,
+				caller: cii.caller,
+				callee: cii.callee,
 				tile,
+				turn: this.state.turn,
+			};
+		} else if (this.state.tiles.length === 0) {
+			// 流局
+
+			this.state.turn = null;
+			this.state.nextTurnAfterAsking = null;
+
+			this.endKyoku();
+
+			return {
+				type: 'ryukyoku' as const,
+			};
+		} else {
+			this.state.turn = this.state.nextTurnAfterAsking!;
+			this.state.nextTurnAfterAsking = null;
+
+			const tile = this.tsumo();
+
+			return {
+				type: 'tsumo' as const,
+				house: this.state.turn,
+				tile,
+				turn: this.state.turn,
 			};
 		}
-
-		clearAsking();
-		this.state.turn = this.state.nextTurnAfterAsking;
-		this.state.nextTurnAfterAsking = null;
-
-		const tile = this.tsumo();
-
-		return {
-			type: 'tsumo',
-			house: this.state.turn,
-			tile,
-		};
 	}
 
 	public createPlayerState(index: 1 | 2 | 3 | 4): PlayerState {
diff --git a/packages/misskey-mahjong/src/engine.player.ts b/packages/misskey-mahjong/src/engine.player.ts
index ef19e13a9e..415c962928 100644
--- a/packages/misskey-mahjong/src/engine.player.ts
+++ b/packages/misskey-mahjong/src/engine.player.ts
@@ -151,7 +151,12 @@ export class PlayerGameEngine {
 	 * @param callers ロンした人
 	 * @param callee 牌を捨てた人
 	 */
-	public commit_ron(callers: House[], callee: House) {
+	public commit_ron(callers: House[], callee: House, handTiles: {
+		e: Tile[];
+		s: Tile[];
+		w: Tile[];
+		n: Tile[];
+	}) {
 		console.log('commit_ron', this.state.turn, callers, callee);
 
 		this.state.canRonSource = null;
@@ -161,13 +166,13 @@ export class PlayerGameEngine {
 		for (const house of callers) {
 			const yakus = YAKU_DEFINITIONS.filter(yaku => yaku.calc({
 				house: house,
-				handTiles: this.state.handTiles[house],
+				handTiles: handTiles[house],
 				huros: this.state.huros[house],
 				tsumoTile: null,
 				ronTile: this.state.hoTiles[callee].at(-1)!,
 				riichi: this.state.riichis[house],
 			}));
-			console.log('yakus', yakus);
+			console.log('yakus', house, yakus);
 		}
 	}