diff --git a/apps/client/src/scenes/game/GameManager.ts b/apps/client/src/scenes/game/GameManager.ts
index e560ca8..9a1b14e 100644
--- a/apps/client/src/scenes/game/GameManager.ts
+++ b/apps/client/src/scenes/game/GameManager.ts
@@ -5,13 +5,11 @@
  */
 import { Application, Container, Ticker } from "pixi.js";
 import { socketManager } from "@client/network/SocketManager";
-import { config } from "@repo/shared";
 import { GameMapController } from "./entities/map/GameMapController";
-import { BombController } from "./entities/bomb/BombController";
-import { LocalPlayerController } from "./entities/player/PlayerController";
 import { GameTimer } from "./application/GameTimer";
 import { GameNetworkSync } from "./application/GameNetworkSync";
 import { GameLoop } from "./application/GameLoop";
+import { BombManager } from "./application/BombManager";
 import type { GamePlayers } from "./application/game.types";
 
 /** ゲームシーンの実行ライフサイクルを管理するマネージャー */
@@ -23,8 +21,7 @@
   private container: HTMLDivElement;
   private gameMap!: GameMapController;
   private timer = new GameTimer();
-  private bombs: BombController[] = [];
-  private lastBombPlacedElapsedMs = Number.NEGATIVE_INFINITY;
+  private bombManager: BombManager | null = null;
   private networkSync: GameNetworkSync | null = null;
   private gameLoop: GameLoop | null = null;
 
@@ -39,27 +36,7 @@
   }
 
   public placeBomb() {
-    const me = this.players[this.myId];
-    if (!me || !(me instanceof LocalPlayerController)) return;
-
-    const elapsedMs = this.timer.getElapsedMs();
-    const { BOMB_COOLDOWN_MS, BOMB_FUSE_MS, BOMB_RADIUS_GRID } = config.GAME_CONFIG;
-    if (elapsedMs - this.lastBombPlacedElapsedMs < BOMB_COOLDOWN_MS) {
-      return;
-    }
-
-    const position = me.getPosition();
-    const bomb = new BombController({
-      x: position.x,
-      y: position.y,
-      radiusGrid: BOMB_RADIUS_GRID,
-      placedAtElapsedMs: elapsedMs,
-      explodeAtElapsedMs: elapsedMs + BOMB_FUSE_MS,
-    });
-
-    this.bombs.push(bomb);
-    this.worldContainer.addChild(bomb.getDisplayObject());
-    this.lastBombPlacedElapsedMs = elapsedMs;
+    this.bombManager?.placeBomb();
   }
   
   // 入力と状態管理
@@ -112,6 +89,13 @@
       getJoystickInput: () => this.joystickInput,
     });
 
+    this.bombManager = new BombManager({
+      worldContainer: this.worldContainer,
+      players: this.players,
+      myId: this.myId,
+      getElapsedMs: () => this.timer.getElapsedMs(),
+    });
+
     // サーバーへゲーム準備完了を通知
     socketManager.game.readyForGame();
 
@@ -132,28 +116,9 @@
    */
   private tick = (ticker: Ticker) => {
     this.gameLoop?.tick(ticker);
-    this.updateBombs();
+    this.bombManager?.tick();
   };
 
-  private updateBombs() {
-    const elapsedMs = this.timer.getElapsedMs();
-
-    const nextBombs: BombController[] = [];
-    this.bombs.forEach((bomb) => {
-      bomb.tick(elapsedMs);
-
-      if (bomb.isFinished()) {
-        this.worldContainer.removeChild(bomb.getDisplayObject());
-        bomb.destroy();
-        return;
-      }
-
-      nextBombs.push(bomb);
-    });
-
-    this.bombs = nextBombs;
-  }
-
   /**
    * クリーンアップ処理（コンポーネントアンマウント時）
    */
@@ -162,8 +127,8 @@
     if (this.isInitialized) {
       this.app.destroy(true, { children: true });
     }
-    this.bombs.forEach((bomb) => bomb.destroy());
-    this.bombs = [];
+    this.bombManager?.destroy();
+    this.bombManager = null;
     this.players = {};
     
     // イベント購読の解除
diff --git a/apps/client/src/scenes/game/application/BombManager.ts b/apps/client/src/scenes/game/application/BombManager.ts
new file mode 100644
index 0000000..0b6ef4d
--- /dev/null
+++ b/apps/client/src/scenes/game/application/BombManager.ts
@@ -0,0 +1,84 @@
+/**
+ * BombManager
+ * 爆弾エンティティの生成，更新，破棄を管理する
+ * クールダウンと設置位置解決をまとめて扱う
+ */
+import type { Container } from "pixi.js";
+import { config } from "@repo/shared";
+import { LocalPlayerController } from "@client/scenes/game/entities/player/PlayerController";
+import { BombController } from "@client/scenes/game/entities/bomb/BombController";
+import type { GamePlayers } from "./game.types";
+
+type BombManagerOptions = {
+  worldContainer: Container;
+  players: GamePlayers;
+  myId: string;
+  getElapsedMs: () => number;
+};
+
+/** 爆弾エンティティのライフサイクルを管理する */
+export class BombManager {
+  private worldContainer: Container;
+  private players: GamePlayers;
+  private myId: string;
+  private getElapsedMs: () => number;
+  private bombs: BombController[] = [];
+  private lastBombPlacedElapsedMs = Number.NEGATIVE_INFINITY;
+
+  constructor({ worldContainer, players, myId, getElapsedMs }: BombManagerOptions) {
+    this.worldContainer = worldContainer;
+    this.players = players;
+    this.myId = myId;
+    this.getElapsedMs = getElapsedMs;
+  }
+
+  /** 自プレイヤー位置に爆弾を設置する */
+  public placeBomb(): void {
+    const me = this.players[this.myId];
+    if (!me || !(me instanceof LocalPlayerController)) return;
+
+    const elapsedMs = this.getElapsedMs();
+    const { BOMB_COOLDOWN_MS, BOMB_FUSE_MS, BOMB_RADIUS_GRID } = config.GAME_CONFIG;
+    if (elapsedMs - this.lastBombPlacedElapsedMs < BOMB_COOLDOWN_MS) {
+      return;
+    }
+
+    const position = me.getPosition();
+    const bomb = new BombController({
+      x: position.x,
+      y: position.y,
+      radiusGrid: BOMB_RADIUS_GRID,
+      explodeAtElapsedMs: elapsedMs + BOMB_FUSE_MS,
+    });
+
+    this.bombs.push(bomb);
+    this.worldContainer.addChild(bomb.getDisplayObject());
+    this.lastBombPlacedElapsedMs = elapsedMs;
+  }
+
+  /** 爆弾状態を更新し終了済みを破棄する */
+  public tick(): void {
+    const elapsedMs = this.getElapsedMs();
+
+    const nextBombs: BombController[] = [];
+    this.bombs.forEach((bomb) => {
+      bomb.tick(elapsedMs);
+
+      if (bomb.isFinished()) {
+        this.worldContainer.removeChild(bomb.getDisplayObject());
+        bomb.destroy();
+        return;
+      }
+
+      nextBombs.push(bomb);
+    });
+
+    this.bombs = nextBombs;
+  }
+
+  /** 管理中の爆弾をすべて破棄する */
+  public destroy(): void {
+    this.bombs.forEach((bomb) => bomb.destroy());
+    this.bombs = [];
+  }
+}
diff --git a/apps/client/src/scenes/game/entities/bomb/BombController.ts b/apps/client/src/scenes/game/entities/bomb/BombController.ts
index fe2cf19..5ef5991 100644
--- a/apps/client/src/scenes/game/entities/bomb/BombController.ts
+++ b/apps/client/src/scenes/game/entities/bomb/BombController.ts
@@ -10,7 +10,6 @@
   x: number;
   y: number;
   radiusGrid: number;
-  placedAtElapsedMs: number;
   explodeAtElapsedMs: number;
 };
 
@@ -19,8 +18,8 @@
   private readonly model: BombModel;
   private readonly view: BombView;
 
-  constructor({ x, y, radiusGrid, placedAtElapsedMs, explodeAtElapsedMs }: BombControllerOptions) {
-    this.model = new BombModel({ x, y, radiusGrid, placedAtElapsedMs, explodeAtElapsedMs });
+  constructor({ x, y, radiusGrid, explodeAtElapsedMs }: BombControllerOptions) {
+    this.model = new BombModel({ x, y, radiusGrid, explodeAtElapsedMs });
     this.view = new BombView();
 
     const pos = this.model.getPosition();
diff --git a/apps/client/src/scenes/game/entities/bomb/BombModel.ts b/apps/client/src/scenes/game/entities/bomb/BombModel.ts
index 82768f0..339b124 100644
--- a/apps/client/src/scenes/game/entities/bomb/BombModel.ts
+++ b/apps/client/src/scenes/game/entities/bomb/BombModel.ts
@@ -3,6 +3,7 @@
  * 爆弾の状態遷移と時間管理を担うモデル
  * 設置中 → 爆発中 → 終了 のライフサイクルを管理する
  */
+/** 爆弾の状態を表す型 */
 export type BombState = "armed" | "exploded" | "finished";
 
 const EXPLOSION_VISIBLE_MS = 250;
@@ -11,7 +12,6 @@
   x: number;
   y: number;
   radiusGrid: number;
-  placedAtElapsedMs: number;
   explodeAtElapsedMs: number;
 };
 
@@ -20,15 +20,13 @@
   private x: number;
   private y: number;
   private radiusGrid: number;
-  private placedAtElapsedMs: number;
   private explodeAtElapsedMs: number;
   private state: BombState = "armed";
 
-  constructor({ x, y, radiusGrid, placedAtElapsedMs, explodeAtElapsedMs }: BombModelOptions) {
+  constructor({ x, y, radiusGrid, explodeAtElapsedMs }: BombModelOptions) {
     this.x = x;
     this.y = y;
     this.radiusGrid = radiusGrid;
-    this.placedAtElapsedMs = placedAtElapsedMs;
     this.explodeAtElapsedMs = explodeAtElapsedMs;
   }
 
@@ -61,10 +59,6 @@
     return this.state === "finished";
   }
 
-  public getPlacedAtElapsedMs(): number {
-    return this.placedAtElapsedMs;
-  }
-
   public getExplodeAtElapsedMs(): number {
     return this.explodeAtElapsedMs;
   }
diff --git a/apps/client/src/scenes/game/entities/bomb/BombView.ts b/apps/client/src/scenes/game/entities/bomb/BombView.ts
index d88d673..7021e18 100644
--- a/apps/client/src/scenes/game/entities/bomb/BombView.ts
+++ b/apps/client/src/scenes/game/entities/bomb/BombView.ts
@@ -13,6 +13,8 @@
 
   private bombGraphic: Graphics;
   private explosionGraphic: Graphics;
+  private lastRenderedState: BombState | null = null;
+  private lastRenderedRadiusGrid: number | null = null;
 
   constructor() {
     this.displayObject = new Container();
@@ -31,10 +33,17 @@
   }
 
   public renderState(state: BombState, radiusGrid: number): void {
+    if (this.lastRenderedState === state && this.lastRenderedRadiusGrid === radiusGrid) {
+      return;
+    }
+
     const { GRID_CELL_SIZE } = config.GAME_CONFIG;
     const bombRadiusPx = GRID_CELL_SIZE * 0.2;
     const explosionRadiusPx = radiusGrid * GRID_CELL_SIZE;
 
+    this.lastRenderedState = state;
+    this.lastRenderedRadiusGrid = radiusGrid;
+
     this.bombGraphic.clear();
     this.explosionGraphic.clear();
 
diff --git a/packages/shared/src/config/gameConfig.ts b/packages/shared/src/config/gameConfig.ts
index b4b821d..b73e6ca 100644
--- a/packages/shared/src/config/gameConfig.ts
+++ b/packages/shared/src/config/gameConfig.ts
@@ -1,3 +1,9 @@
+/**
+ * gameConfig
+ * ゲーム進行，描画，入力に関する共有設定値を定義する
+ * クライアントとサーバーで参照する定数群を提供する
+ */
+/** ゲーム全体で利用する共有設定値 */
 export const GAME_CONFIG = {
   // ゲーム設定
   MAX_PLAYERS_PER_ROOM: 100,  // ルーム収容人数設定