diff --git a/apps/server/src/domains/game/GameHandler.ts b/apps/server/src/domains/game/GameHandler.ts
new file mode 100644
index 0000000..3d67bd4
--- /dev/null
+++ b/apps/server/src/domains/game/GameHandler.ts
@@ -0,0 +1,65 @@
+import { Server, Socket } from "socket.io";
+import { GameManager } from "./GameManager";
+import { RoomManager } from "../room/RoomManager";
+import { SocketEvents } from "@repo/shared/src/protocol/events";
+import { RoomStatus } from "@repo/shared/src/domains/room/room.type";
+import type { MovePayload } from "@repo/shared/src/domains/player/player.type";
+
+export const registerGameHandlers = (io: Server, socket: Socket, gameManager: GameManager, roomManager: RoomManager) => {
+  
+  // ゲーム開始要求処理
+  socket.on(SocketEvents.START_GAME, () => {
+    const room = roomManager.getRoomByOwnerId(socket.id);
+    
+    if (room) {
+      room.status = RoomStatus.PLAYING;
+
+      const playerIds = room.players.map((p: { id: string }) => p.id);
+      
+      // 同ルーム全プレイヤーのゲーム管理登録
+      room.players.forEach((p: { id: string }) => {
+        gameManager.addPlayer(p.id);
+      });
+
+      // ルーム全員向けゲーム開始通知
+      io.to(room.roomId).emit(SocketEvents.GAME_START);
+
+      // 20Hzのゲームループを開始し、毎フレームの送信処理を定義
+      gameManager.startGameLoop(room.roomId, playerIds, (tickData) => {
+        
+        // 1. 各プレイヤーの最新座標をクライアントに送信
+        tickData.players.forEach((playerData) => {
+          io.to(room.roomId).emit(SocketEvents.UPDATE_PLAYER, playerData);
+        });
+
+        // 2. 差分があれば、ルーム内の全員に一斉送信
+        if (tickData.cellUpdates.length > 0) {
+          io.to(room.roomId).emit(SocketEvents.UPDATE_MAP_CELLS, tickData.cellUpdates);
+        }
+        
+      });
+    }
+  });
+
+  // 画面準備完了通知受信時初期データ返却
+  socket.on(SocketEvents.READY_FOR_GAME, () => {
+    const allPlayers = gameManager.getAllPlayers();
+    socket.emit(SocketEvents.CURRENT_PLAYERS, allPlayers);
+  });
+
+  // ゲームプレイ中イベント群
+  socket.on(SocketEvents.MOVE, (data: MovePayload) => {
+    gameManager.movePlayer(socket.id, data.x, data.y);
+  });
+
+};
+
+/**
+ * 切断時のゲームクリーンアップ処理
+ */
+export const handleGameDisconnect = (io: Server, gameManager: GameManager, playerId: string) => {
+  // ゲームからの除外処理
+  gameManager.removePlayer(playerId);
+  // 全体にプレイヤー削除を通知
+  io.emit(SocketEvents.REMOVE_PLAYER, playerId);
+};
\ No newline at end of file
diff --git a/apps/server/src/domains/game/GameLoop.ts b/apps/server/src/domains/game/GameLoop.ts
new file mode 100644
index 0000000..50c81f8
--- /dev/null
+++ b/apps/server/src/domains/game/GameLoop.ts
@@ -0,0 +1,76 @@
+import { Player } from "./entities/Player.js";
+import { MapStore } from "./states/MapStore";
+import { getGridIndexFromPosition } from "@repo/shared/src/domains/gridMap/gridMap.logic";
+import type { CellUpdate } from "@repo/shared/src/domains/gridMap/gridMap.type";
+
+// コールバックで渡すデータの型定義
+export interface TickData {
+  players: {
+    id: string;
+    x: number;
+    y: number;
+    teamId: number;
+  }[];
+  cellUpdates: CellUpdate[];
+}
+
+export class GameLoop {
+  private loopId: NodeJS.Timeout | null = null;
+
+  constructor(
+    private roomId: string,
+    private tickRate: number,
+    private playerIds: string[],
+    private players: Map<string, Player>,
+    private mapStore: MapStore,
+    private onTick: (data: TickData) => void
+  ) {}
+
+  start() {
+    // 既にループが回っている場合は何もしない
+    if (this.loopId) return;
+
+    this.loopId = setInterval(() => {
+      const playersData: TickData["players"] = [];
+
+      // 1. 各プレイヤーの座標処理とマス塗りの判定
+      this.playerIds.forEach(id => {
+        const player = this.players.get(id);
+        if (!player) return;
+
+        const gridIndex = getGridIndexFromPosition(player.x, player.y);
+        if (gridIndex !== null) {
+          this.mapStore.paintCell(gridIndex, player.teamId);
+        }
+
+        // 送信用のプレイヤーデータを構築
+        playersData.push({
+          id: player.id,
+          x: player.x,
+          y: player.y,
+          teamId: player.teamId,
+        });
+      });
+
+      // 2. マスの差分（Diff）を取得
+      const cellUpdates = this.mapStore.getAndClearUpdates();
+
+      // 3. 通信層（GameHandler）へデータを渡す
+      this.onTick({
+        players: playersData,
+        cellUpdates: cellUpdates,
+      });
+      
+    }, this.tickRate);
+
+    console.log(`[GameLoop] Started for room: ${this.roomId} at ${this.tickRate}ms`);
+  }
+
+  stop() {
+    if (this.loopId) {
+      clearInterval(this.loopId);
+      this.loopId = null;
+      console.log(`[GameLoop] Stopped for room: ${this.roomId}`);
+    }
+  }
+}
\ No newline at end of file
diff --git a/apps/server/src/domains/game/GameManager.ts b/apps/server/src/domains/game/GameManager.ts
new file mode 100644
index 0000000..7b010e1
--- /dev/null
+++ b/apps/server/src/domains/game/GameManager.ts
@@ -0,0 +1,106 @@
+import { Player } from "./entities/Player.js";
+import { GAME_CONFIG } from "@repo/shared/src/config/gameConfig";
+import { MapStore } from "./states/MapStore";
+import { getGridIndexFromPosition } from "@repo/shared/src/domains/gridMap/gridMap.logic";
+import type { CellUpdate } from "@repo/shared/src/domains/gridMap/gridMap.type";
+import { GameLoop, type TickData } from "./GameLoop";
+
+// プレイヤー集合の生成・更新・参照管理クラス
+export class GameManager {
+  private players: Map<string, Player>;
+  private mapStore: MapStore;
+  private gameLoops: Map<string, GameLoop>; // NodeJS.Timeout から変更
+
+  constructor() {
+    this.players = new Map();
+    this.mapStore = new MapStore();
+    this.gameLoops = new Map();
+  }
+
+  // 新規プレイヤー登録と初期位置設定処理
+  addPlayer(id: string): Player {
+    const player = new Player(id);
+    player.x = GAME_CONFIG.MAP_WIDTH / 2;
+    player.y = GAME_CONFIG.MAP_HEIGHT / 2;
+    this.players.set(id, player);
+    return player;
+  }
+
+  // プレイヤー登録解除処理
+  removePlayer(id: string) {
+    this.players.delete(id);
+  }
+
+  // 指定IDプレイヤー参照取得
+  getPlayer(id: string) {
+    return this.players.get(id);
+  }
+
+  // 指定プレイヤー座標更新処理
+  movePlayer(id: string, x: number, y: number) {
+    const player = this.players.get(id);
+    if (player) {
+      console.log(`Move Request -> ID:${id.slice(0,4)} x:${Math.round(x)} y:${Math.round(y)}`);
+      if (typeof x !== "number" || typeof y !== "number" || isNaN(x) || isNaN(y)) {
+        console.log("⚠️ 無効なデータなので無視しました");
+        return;
+      }
+      player.x = x;
+      player.y = y;
+    }
+  }
+
+  /**
+   * 20Hz固定のゲームループを開始する
+   * @param roomId ルームID
+   * @param playerIds このルームに参加しているプレイヤーのIDリスト
+   * @param onTick 毎フレーム実行される送信用のコールバック関数
+   */
+  startGameLoop(roomId: string, playerIds: string[], onTick: (data: TickData) => void) {
+    if (this.gameLoops.has(roomId)) return;
+
+    const tickRate = GAME_CONFIG.PLAYER_POSITION_UPDATE_MS;
+    
+    // GameLoopインスタンスを生成し、参照を渡す
+    const loop = new GameLoop(
+      roomId,
+      tickRate,
+      playerIds,
+      this.players,
+      this.mapStore,
+      onTick
+    );
+
+    loop.start();
+    this.gameLoops.set(roomId, loop);
+  }
+
+  /**
+   * ゲームループを停止する
+   */
+  stopGameLoop(roomId: string) {
+    const loop = this.gameLoops.get(roomId);
+    if (loop) {
+      loop.stop();
+      this.gameLoops.delete(roomId);
+    }
+  }
+
+  // 登録中全プレイヤー配列取得
+  getAllPlayers() {
+    return Array.from(this.players.values());
+  }
+
+  // 【一時的】移動したプレイヤーの足元を塗り、差分を返すメソッド
+  public paintAndGetUpdates(playerId: string): CellUpdate[] {
+    const player = this.players.get(playerId);
+    if (!player) return [];
+
+    const gridIndex = getGridIndexFromPosition(player.x, player.y);
+    if (gridIndex !== null) {
+      this.mapStore.paintCell(gridIndex, player.teamId);
+    }
+
+    return this.mapStore.getAndClearUpdates();
+  }
+}
\ No newline at end of file
diff --git a/apps/server/src/domains/game/entities/Player.ts b/apps/server/src/domains/game/entities/Player.ts
new file mode 100644
index 0000000..edc7976
--- /dev/null
+++ b/apps/server/src/domains/game/entities/Player.ts
@@ -0,0 +1,18 @@
+import type { PlayerData } from "@repo/shared/src/domains/player/player.type";
+import { GAME_CONFIG } from "@repo/shared/src/config/gameConfig";
+
+// サーバー側保持プレイヤー状態モデル
+export class Player implements PlayerData {
+  public id: string;
+  public x: number = 0;
+  public y: number = 0;
+  public teamId: number;
+
+  constructor(id: string) {
+    this.id = id;
+    
+    // GAME_CONFIGからチーム数を動的に取得して割り当て
+    const teamCount = GAME_CONFIG.TEAM_COLORS.length;
+    this.teamId = Math.floor(Math.random() * teamCount);
+  }
+}
\ No newline at end of file
diff --git a/apps/server/src/domains/game/states/MapStore.ts b/apps/server/src/domains/game/states/MapStore.ts
new file mode 100644
index 0000000..4f6f2be
--- /dev/null
+++ b/apps/server/src/domains/game/states/MapStore.ts
@@ -0,0 +1,36 @@
+// apps/server/src/states/MapStore.ts
+import type { CellUpdate } from "@repo/shared/src/domains/gridMap/gridMap.type";
+import { GAME_CONFIG } from "@repo/shared/src/config/gameConfig";
+
+export class MapStore {
+  // 全マスの現在の色（teamId）を保持
+  private gridColors: number[];
+  // 次回の送信ループで送る差分リスト
+  private pendingUpdates: CellUpdate[];
+
+  constructor() {
+    // 初期状態は -1 (無色) などで初期化
+    const totalCells = GAME_CONFIG.GRID_COLS * GAME_CONFIG.GRID_ROWS;
+    this.gridColors = new Array(totalCells).fill(-1);
+    this.pendingUpdates = [];
+  }
+
+  /**
+   * マスを塗り、色が変化した場合のみ差分キューに追加する
+   */
+  public paintCell(index: number, teamId: number): void {
+    if (this.gridColors[index] !== teamId) {
+      this.gridColors[index] = teamId;
+      this.pendingUpdates.push({ index, teamId });
+    }
+  }
+
+  /**
+   * 溜まっている差分を取得し、キューをクリアする（ループ送信時に使用）
+   */
+  public getAndClearUpdates(): CellUpdate[] {
+    const updates = [...this.pendingUpdates];
+    this.pendingUpdates = [];
+    return updates;
+  }
+}
\ No newline at end of file
diff --git a/apps/server/src/domains/room/RoomHandler.ts b/apps/server/src/domains/room/RoomHandler.ts
new file mode 100644
index 0000000..d210e01
--- /dev/null
+++ b/apps/server/src/domains/room/RoomHandler.ts
@@ -0,0 +1,33 @@
+import { Server, Socket } from "socket.io";
+import { RoomManager } from "./RoomManager";
+import { SocketEvents } from "@repo/shared/src/protocol/events";
+import type { JoinRoomPayload } from "@repo/shared/src/domains/room/room.type";
+
+export const registerRoomHandlers = (io: Server, socket: Socket, roomManager: RoomManager) => {
+  
+  socket.on(SocketEvents.JOIN_ROOM, (data: JoinRoomPayload) => {
+    const { roomId, playerName } = data;
+    
+    socket.join(roomId);
+
+    // RoomManagerにデータ操作を依頼
+    const room = roomManager.addPlayerToRoom(roomId, socket.id, playerName);
+
+    // ルーム内全員向け最新状態配信
+    io.to(roomId).emit(SocketEvents.ROOM_UPDATE, room);
+  });
+
+};
+
+/**
+ * 切断時のルームクリーンアップ処理
+ */
+export const handleRoomDisconnect = (io: Server, socket: Socket, roomManager: RoomManager) => {
+  // ルームからの除外処理
+  const updatedRooms = roomManager.removePlayer(socket.id);
+  
+  // 更新があったルーム（オーナー変更など）にのみ通知を飛ばす
+  updatedRooms.forEach(room => {
+    io.to(room.roomId).emit(SocketEvents.ROOM_UPDATE, room);
+  });
+};
\ No newline at end of file
diff --git a/apps/server/src/domains/room/RoomManager.ts b/apps/server/src/domains/room/RoomManager.ts
new file mode 100644
index 0000000..3be6e62
--- /dev/null
+++ b/apps/server/src/domains/room/RoomManager.ts
@@ -0,0 +1,66 @@
+import { Room, RoomStatus, RoomMember } from "@repo/shared/src/domains/room/room.type";
+import { GAME_CONFIG } from "@repo/shared/src/config/gameConfig";
+
+export class RoomManager {
+  private rooms: Map<string, Room> = new Map();
+
+  // ルームにプレイヤーを追加（なければ作成）
+  public addPlayerToRoom(roomId: string, socketId: string, playerName: string): Room {
+    let room = this.rooms.get(roomId);
+    if (!room) {
+      room = {
+        roomId: roomId,
+        ownerId: socketId,
+        players: [],
+        status: RoomStatus.WAITING,
+        maxPlayers: GAME_CONFIG.MAX_PLAYERS_PER_ROOM
+      };
+      this.rooms.set(roomId, room);
+    }
+
+    const newPlayer: RoomMember = {
+      id: socketId,
+      name: playerName,
+      isOwner: room.ownerId === socketId,
+      isReady: false
+    };
+    room.players.push(newPlayer);
+
+    return room;
+  }
+
+  // プレイヤーをルームから削除し、更新があったルームの配列を返す
+  public removePlayer(socketId: string): Room[] {
+    const updatedRooms: Room[] = [];
+    
+    for (const [roomId, room] of this.rooms.entries()) {
+      const playerIndex = room.players.findIndex(p => p.id === socketId);
+      if (playerIndex !== -1) {
+        room.players.splice(playerIndex, 1);
+        
+        if (room.players.length === 0) {
+          // 空ルーム削除
+          this.rooms.delete(roomId);
+        } else {
+          // オーナー切断時所有権移譲処理
+          if (room.ownerId === socketId) {
+            room.ownerId = room.players[0].id;
+            room.players[0].isOwner = true;
+          }
+          updatedRooms.push(room);
+        }
+      }
+    }
+    return updatedRooms;
+  }
+
+  // オーナーIDからルームを取得
+  public getRoomByOwnerId(ownerId: string): Room | undefined {
+    for (const room of this.rooms.values()) {
+      if (room.ownerId === ownerId) {
+        return room;
+      }
+    }
+    return undefined;
+  }
+}
\ No newline at end of file
diff --git a/apps/server/src/entities/Player.ts b/apps/server/src/entities/Player.ts
deleted file mode 100644
index edc7976..0000000
--- a/apps/server/src/entities/Player.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-import type { PlayerData } from "@repo/shared/src/domains/player/player.type";
-import { GAME_CONFIG } from "@repo/shared/src/config/gameConfig";
-
-// サーバー側保持プレイヤー状態モデル
-export class Player implements PlayerData {
-  public id: string;
-  public x: number = 0;
-  public y: number = 0;
-  public teamId: number;
-
-  constructor(id: string) {
-    this.id = id;
-    
-    // GAME_CONFIGからチーム数を動的に取得して割り当て
-    const teamCount = GAME_CONFIG.TEAM_COLORS.length;
-    this.teamId = Math.floor(Math.random() * teamCount);
-  }
-}
\ No newline at end of file
diff --git a/apps/server/src/handlers/GameHandler.ts b/apps/server/src/handlers/GameHandler.ts
deleted file mode 100644
index c26cf65..0000000
--- a/apps/server/src/handlers/GameHandler.ts
+++ /dev/null
@@ -1,70 +0,0 @@
-import { Server, Socket } from "socket.io";
-import { GameManager } from "../managers/GameManager.js";
-import { RoomManager } from "../managers/RoomManager.js";
-import { SocketEvents } from "@repo/shared/src/protocol/events";
-import { RoomStatus } from "@repo/shared/src/domains/room/room.type";
-import type { MovePayload } from "@repo/shared/src/domains/player/player.type";
-
-export const registerGameHandlers = (io: Server, socket: Socket, gameManager: GameManager, roomManager: RoomManager) => {
-  
-  // ゲーム開始要求処理
-  socket.on(SocketEvents.START_GAME, () => {
-    const room = roomManager.getRoomByOwnerId(socket.id);
-    
-    if (room) {
-      room.status = RoomStatus.PLAYING;
-      
-      // 同ルーム全プレイヤーのゲーム管理登録
-      room.players.forEach((p: { id: string }) => {
-        gameManager.addPlayer(p.id);
-      });
-
-      // ルーム全員向けゲーム開始通知
-      io.to(room.roomId).emit(SocketEvents.GAME_START);
-    }
-  });
-
-  // 画面準備完了通知受信時初期データ返却
-  socket.on(SocketEvents.READY_FOR_GAME, () => {
-    const allPlayers = gameManager.getAllPlayers();
-    socket.emit(SocketEvents.CURRENT_PLAYERS, allPlayers);
-  });
-
-  // ゲームプレイ中イベント群
-  socket.on(SocketEvents.MOVE, (data: MovePayload) => {
-    gameManager.movePlayer(socket.id, data.x, data.y);
-    
-    const updatedPlayer = gameManager.getPlayer(socket.id);
-    if (updatedPlayer) {
-      const myRooms = Array.from(socket.rooms).filter(r => r !== socket.id);
-      const targetRoom = myRooms.length > 0 ? myRooms[0] : null;
-
-      if (targetRoom) {
-        io.to(targetRoom).emit(SocketEvents.UPDATE_PLAYER, { 
-          id: socket.id, 
-          x: updatedPlayer.x, 
-          y: updatedPlayer.y 
-        });
-
-        // ② 【新規】マス目の更新と差分送信のテスト
-        const cellUpdates = gameManager.paintAndGetUpdates(socket.id);
-        if (cellUpdates.length > 0) {
-          io.to(targetRoom).emit(SocketEvents.UPDATE_MAP_CELLS, cellUpdates);
-          // ログを出してサーバー側で送信されているか確認すると便利です
-          console.log(`[MAP_UPDATE] Sent ${cellUpdates.length} updates to room ${targetRoom}`);
-        }
-      }
-    }
-  });
-
-};
-
-/**
- * 切断時のゲームクリーンアップ処理
- */
-export const handleGameDisconnect = (io: Server, gameManager: GameManager, playerId: string) => {
-  // ゲームからの除外処理
-  gameManager.removePlayer(playerId);
-  // 全体にプレイヤー削除を通知
-  io.emit(SocketEvents.REMOVE_PLAYER, playerId);
-};
\ No newline at end of file
diff --git a/apps/server/src/handlers/RoomHandler.ts b/apps/server/src/handlers/RoomHandler.ts
deleted file mode 100644
index e3f0e23..0000000
--- a/apps/server/src/handlers/RoomHandler.ts
+++ /dev/null
@@ -1,33 +0,0 @@
-import { Server, Socket } from "socket.io";
-import { RoomManager } from "../managers/RoomManager.js";
-import { SocketEvents } from "@repo/shared/src/protocol/events";
-import type { JoinRoomPayload } from "@repo/shared/src/domains/room/room.type";
-
-export const registerRoomHandlers = (io: Server, socket: Socket, roomManager: RoomManager) => {
-  
-  socket.on(SocketEvents.JOIN_ROOM, (data: JoinRoomPayload) => {
-    const { roomId, playerName } = data;
-    
-    socket.join(roomId);
-
-    // RoomManagerにデータ操作を依頼
-    const room = roomManager.addPlayerToRoom(roomId, socket.id, playerName);
-
-    // ルーム内全員向け最新状態配信
-    io.to(roomId).emit(SocketEvents.ROOM_UPDATE, room);
-  });
-
-};
-
-/**
- * 切断時のルームクリーンアップ処理
- */
-export const handleRoomDisconnect = (io: Server, socket: Socket, roomManager: RoomManager) => {
-  // ルームからの除外処理
-  const updatedRooms = roomManager.removePlayer(socket.id);
-  
-  // 更新があったルーム（オーナー変更など）にのみ通知を飛ばす
-  updatedRooms.forEach(room => {
-    io.to(room.roomId).emit(SocketEvents.ROOM_UPDATE, room);
-  });
-};
\ No newline at end of file
diff --git a/apps/server/src/index.ts b/apps/server/src/index.ts
index 314f10e..dc4676b 100644
--- a/apps/server/src/index.ts
+++ b/apps/server/src/index.ts
@@ -1,7 +1,8 @@
 import { Server } from "socket.io";
 import { createServer } from "http";
-import { GameManager } from "./managers/GameManager.js";
-import { SocketManager } from "./network/SocketManager.js";
+import { GameManager } from "./domains/game/GameManager";
+import { RoomManager } from "./domains/room/RoomManager";
+import { SocketManager } from "./network/SocketManager";
 
 // サーバー待受ポート
 const PORT = 3000;
@@ -18,7 +19,8 @@
 
 // ゲーム管理・通信管理クラス初期化
 const gameManager = new GameManager();
-const socketManager = new SocketManager(io, gameManager);
+const roomManager = new RoomManager();
+const socketManager = new SocketManager(io, gameManager, roomManager);
 
 socketManager.initialize();
 
diff --git a/apps/server/src/managers/GameManager.ts b/apps/server/src/managers/GameManager.ts
deleted file mode 100644
index 152cbe0..0000000
--- a/apps/server/src/managers/GameManager.ts
+++ /dev/null
@@ -1,76 +0,0 @@
-import { Player } from "../entities/Player.js";
-import { GAME_CONFIG } from "@repo/shared/src/config/gameConfig";
-import { MapStore } from "../states/MapStore";
-import { getGridIndexFromPosition } from "@repo/shared/src/domains/gridMap/gridMap.logic";
-import type { CellUpdate } from "@repo/shared/src/domains/gridMap/gridMap.type";
-
-// プレイヤー集合の生成・更新・参照管理クラス
-export class GameManager {
-  private players: Map<string, Player>;
-  private mapStore: MapStore;
-
-  constructor() {
-    this.players = new Map();
-    this.mapStore = new MapStore();
-  }
-
-  // 新規プレイヤー登録と初期位置設定処理
-  addPlayer(id: string): Player {
-    const player = new Player(id);
-    
-    // 初期スポーン位置
-    player.x = GAME_CONFIG.MAP_WIDTH / 2;
-    player.y = GAME_CONFIG.MAP_HEIGHT / 2;
-    
-    this.players.set(id, player);
-    return player;
-  }
-
-  // プレイヤー登録解除処理
-  removePlayer(id: string) {
-    this.players.delete(id);
-  }
-
-  // 指定IDプレイヤー参照取得
-  getPlayer(id: string) {
-    return this.players.get(id);
-  }
-
-  // 指定プレイヤー座標更新処理
-  movePlayer(id: string, x: number, y: number) {
-    const player = this.players.get(id);
-    if (player) {
-      
-      // 受信移動要求ログ
-      console.log(`Move Request -> ID:${id.slice(0,4)} x:${Math.round(x)} y:${Math.round(y)}`);
-
-      // 無効座標データ防御チェック
-      if (typeof x !== "number" || typeof y !== "number" || isNaN(x) || isNaN(y)) {
-        console.log("⚠️ 無効なデータなので無視しました");
-        return;
-      }
-
-      // クライアント送信絶対座標の直接反映
-      player.x = x;
-      player.y = y;
-    }
-  }
-
-  // 登録中全プレイヤー配列取得
-  getAllPlayers() {
-    return Array.from(this.players.values());
-  }
-
-  // 【一時的】移動したプレイヤーの足元を塗り、差分を返すメソッド
-  public paintAndGetUpdates(playerId: string): CellUpdate[] {
-    const player = this.players.get(playerId);
-    if (!player) return [];
-
-    const gridIndex = getGridIndexFromPosition(player.x, player.y);
-    if (gridIndex !== null) {
-      this.mapStore.paintCell(gridIndex, player.teamId);
-    }
-
-    return this.mapStore.getAndClearUpdates();
-  }
-}
\ No newline at end of file
diff --git a/apps/server/src/managers/RoomManager.ts b/apps/server/src/managers/RoomManager.ts
deleted file mode 100644
index 3be6e62..0000000
--- a/apps/server/src/managers/RoomManager.ts
+++ /dev/null
@@ -1,66 +0,0 @@
-import { Room, RoomStatus, RoomMember } from "@repo/shared/src/domains/room/room.type";
-import { GAME_CONFIG } from "@repo/shared/src/config/gameConfig";
-
-export class RoomManager {
-  private rooms: Map<string, Room> = new Map();
-
-  // ルームにプレイヤーを追加（なければ作成）
-  public addPlayerToRoom(roomId: string, socketId: string, playerName: string): Room {
-    let room = this.rooms.get(roomId);
-    if (!room) {
-      room = {
-        roomId: roomId,
-        ownerId: socketId,
-        players: [],
-        status: RoomStatus.WAITING,
-        maxPlayers: GAME_CONFIG.MAX_PLAYERS_PER_ROOM
-      };
-      this.rooms.set(roomId, room);
-    }
-
-    const newPlayer: RoomMember = {
-      id: socketId,
-      name: playerName,
-      isOwner: room.ownerId === socketId,
-      isReady: false
-    };
-    room.players.push(newPlayer);
-
-    return room;
-  }
-
-  // プレイヤーをルームから削除し、更新があったルームの配列を返す
-  public removePlayer(socketId: string): Room[] {
-    const updatedRooms: Room[] = [];
-    
-    for (const [roomId, room] of this.rooms.entries()) {
-      const playerIndex = room.players.findIndex(p => p.id === socketId);
-      if (playerIndex !== -1) {
-        room.players.splice(playerIndex, 1);
-        
-        if (room.players.length === 0) {
-          // 空ルーム削除
-          this.rooms.delete(roomId);
-        } else {
-          // オーナー切断時所有権移譲処理
-          if (room.ownerId === socketId) {
-            room.ownerId = room.players[0].id;
-            room.players[0].isOwner = true;
-          }
-          updatedRooms.push(room);
-        }
-      }
-    }
-    return updatedRooms;
-  }
-
-  // オーナーIDからルームを取得
-  public getRoomByOwnerId(ownerId: string): Room | undefined {
-    for (const room of this.rooms.values()) {
-      if (room.ownerId === ownerId) {
-        return room;
-      }
-    }
-    return undefined;
-  }
-}
\ No newline at end of file
diff --git a/apps/server/src/network/SocketManager.ts b/apps/server/src/network/SocketManager.ts
index 791be78..8ad1602 100644
--- a/apps/server/src/network/SocketManager.ts
+++ b/apps/server/src/network/SocketManager.ts
@@ -1,19 +1,19 @@
 import { Server, Socket } from "socket.io";
-import { GameManager } from "../managers/GameManager.js";
-import { RoomManager } from "../managers/RoomManager.js";
+import { GameManager } from "../domains/game/GameManager";
+import { RoomManager } from "../domains/room/RoomManager";
 import { SocketEvents } from "@repo/shared/src/protocol/events";
-import { registerRoomHandlers, handleRoomDisconnect } from "../handlers/RoomHandler.js";
-import { registerGameHandlers, handleGameDisconnect } from "../handlers/GameHandler.js";
+import { registerRoomHandlers, handleRoomDisconnect } from "../domains/room/RoomHandler";
+import { registerGameHandlers, handleGameDisconnect } from "../domains/game/GameHandler";
 
 export class SocketManager {
   private io: Server;
   private gameManager: GameManager;
   private roomManager: RoomManager;
 
-  constructor(io: Server, gameManager: GameManager) {
+  constructor(io: Server, gameManager: GameManager, roomManager: RoomManager) {
     this.io = io;
     this.gameManager = gameManager;
-    this.roomManager = new RoomManager();
+    this.roomManager = roomManager;
   }
 
   public initialize() {
diff --git a/apps/server/src/states/MapStore.ts b/apps/server/src/states/MapStore.ts
deleted file mode 100644
index 4f6f2be..0000000
--- a/apps/server/src/states/MapStore.ts
+++ /dev/null
@@ -1,36 +0,0 @@
-// apps/server/src/states/MapStore.ts
-import type { CellUpdate } from "@repo/shared/src/domains/gridMap/gridMap.type";
-import { GAME_CONFIG } from "@repo/shared/src/config/gameConfig";
-
-export class MapStore {
-  // 全マスの現在の色（teamId）を保持
-  private gridColors: number[];
-  // 次回の送信ループで送る差分リスト
-  private pendingUpdates: CellUpdate[];
-
-  constructor() {
-    // 初期状態は -1 (無色) などで初期化
-    const totalCells = GAME_CONFIG.GRID_COLS * GAME_CONFIG.GRID_ROWS;
-    this.gridColors = new Array(totalCells).fill(-1);
-    this.pendingUpdates = [];
-  }
-
-  /**
-   * マスを塗り、色が変化した場合のみ差分キューに追加する
-   */
-  public paintCell(index: number, teamId: number): void {
-    if (this.gridColors[index] !== teamId) {
-      this.gridColors[index] = teamId;
-      this.pendingUpdates.push({ index, teamId });
-    }
-  }
-
-  /**
-   * 溜まっている差分を取得し、キューをクリアする（ループ送信時に使用）
-   */
-  public getAndClearUpdates(): CellUpdate[] {
-    const updates = [...this.pendingUpdates];
-    this.pendingUpdates = [];
-    return updates;
-  }
-}
\ No newline at end of file
diff --git "a/docs/01_Env/ENV_01_\347\222\260\345\242\203\346\247\213\347\257\211\343\203\273\346\212\200\350\241\223\343\202\271\343\202\277\343\203\203\343\202\257.txt" "b/docs/01_Env/ENV_01_\347\222\260\345\242\203\346\247\213\347\257\211\343\203\273\346\212\200\350\241\223\343\202\271\343\202\277\343\203\203\343\202\257.txt"
index ef06a45..cf5888b 100644
--- "a/docs/01_Env/ENV_01_\347\222\260\345\242\203\346\247\213\347\257\211\343\203\273\346\212\200\350\241\223\343\202\271\343\202\277\343\203\203\343\202\257.txt"
+++ "b/docs/01_Env/ENV_01_\347\222\260\345\242\203\346\247\213\347\257\211\343\203\273\346\212\200\350\241\223\343\202\271\343\202\277\343\203\203\343\202\257.txt"
@@ -55,11 +55,13 @@
     │   │
     │   └── server/           # 【権限】バックエンド (Node.js)
     │       ├── src/
-    │       │   ├── entities/   # サーバー側エンティティ (Player)
-    │       │   ├── handlers/   # 処理ハンドラ (GameHandler, RoomHandler)
-    │       │   ├── managers/   # 管理クラス (GameManager, RoomManager)
-    │       │   ├── network/    # WebSocket処理 (SocketManager)
-    │       │   └── index.ts    # エントリーポイント
+    │       │   ├── domains/      # ドメイン別実装
+    │       │   │   ├── game/     # ゲーム進行 (GameHandler, GameLoop, GameManager)
+    │       │   │   │   ├── entities/       # ゲーム内エンティティ (Player)
+    │       │   │   │   └── states/         # ゲーム状態ストア (MapStore)
+    │       │   │   └── room/     # ルーム管理 (RoomHandler, RoomManager)
+    │       │   ├── network/      # WebSocket処理 (SocketManager)
+    │       │   └── index.ts      # エントリーポイント
     │       ├── tsconfig.json
     │       └── package.json
     │