diff --git a/apps/client/src/app.tsx b/apps/client/src/app.tsx
index 8b37e31..b3d47a2 100644
--- a/apps/client/src/app.tsx
+++ b/apps/client/src/app.tsx
@@ -16,8 +16,10 @@
     room,
     myId,
     gameResult,
+    playerName,
     joinErrorMessage,
     isJoining,
+    setPlayerName,
     requestJoin,
     returnToTitle,
   } = useAppFlow();
@@ -29,6 +31,8 @@
     scene = (
       <TitleScene
         onJoin={requestJoin}
+        playerName={playerName}
+        onPlayerNameChange={setPlayerName}
         joinErrorMessage={joinErrorMessage}
         isJoining={isJoining}
       />
diff --git a/apps/client/src/hooks/application/appFlowReducer.ts b/apps/client/src/hooks/application/appFlowReducer.ts
index d9e4478..9d2f46b 100644
--- a/apps/client/src/hooks/application/appFlowReducer.ts
+++ b/apps/client/src/hooks/application/appFlowReducer.ts
@@ -12,6 +12,7 @@
   room: null,
   myId: null,
   gameResult: null,
+  playerName: "",
 };
 
 /** アプリフロー状態をアクションに応じて更新する */
@@ -26,6 +27,13 @@
     };
   }
 
+  if (action.type === "setPlayerName") {
+    return {
+      ...state,
+      playerName: action.playerName,
+    };
+  }
+
   if (action.type === "setRoomAndLobby") {
     return {
       ...state,
@@ -56,6 +64,7 @@
       room: null,
       myId: action.clearMyId ? null : state.myId,
       gameResult: null,
+      playerName: state.playerName,
     };
   }
 
diff --git a/apps/client/src/hooks/types/appFlowState.ts b/apps/client/src/hooks/types/appFlowState.ts
index 16d3356..1901239 100644
--- a/apps/client/src/hooks/types/appFlowState.ts
+++ b/apps/client/src/hooks/types/appFlowState.ts
@@ -12,11 +12,13 @@
   room: domain.room.Room | null;
   myId: string | null;
   gameResult: GameResultPayload | null;
+  playerName: string;
 };
 
 /** アプリフローを更新するアクション型 */
 export type AppFlowAction =
   | { type: "setMyId"; myId: string | null }
+  | { type: "setPlayerName"; playerName: string }
   | { type: "setRoomAndLobby"; room: domain.room.Room }
   | { type: "setPlaying" }
   | { type: "setResult"; result: GameResultPayload }
diff --git a/apps/client/src/hooks/useAppFlow.ts b/apps/client/src/hooks/useAppFlow.ts
index b90b523..cc81f24 100644
--- a/apps/client/src/hooks/useAppFlow.ts
+++ b/apps/client/src/hooks/useAppFlow.ts
@@ -20,8 +20,10 @@
   room: domain.room.Room | null;
   myId: string | null;
   gameResult: GameResultPayload | null;
+  playerName: string;
   joinErrorMessage: string | null;
   isJoining: boolean;
+  setPlayerName: (name: string) => void;
   requestJoin: (payload: domain.room.JoinRoomPayload) => void;
   returnToTitle: (options?: { leaveRoom?: boolean }) => void;
 };
@@ -38,6 +40,7 @@
 type JoinFailure = {
   reason: JoinFailureReason;
   roomId?: string;
+  playerName?: string;
 };
 
 type JoinAction =
@@ -144,6 +147,7 @@
         completeJoinRequest({
           reason: payload.reason,
           roomId: payload.roomId,
+          playerName: payload.playerName,
         });
       };
 
@@ -155,10 +159,21 @@
       }, config.GAME_CONFIG.JOIN_REQUEST_TIMEOUT_MS);
 
       socketManager.title.joinRoom(payload);
+
+      if (payload.playerName.trim() !== "") {
+        dispatchAppFlow({
+          type: "setPlayerName",
+          playerName: payload.playerName,
+        });
+      }
     },
     [completeJoinRequest, joinState.isJoining],
   );
 
+  const setPlayerName = useCallback((name: string) => {
+    dispatchAppFlow({ type: "setPlayerName", playerName: name });
+  }, []);
+
   const returnToTitle = useCallback(
     (options?: { leaveRoom?: boolean }) => {
       completeJoinRequest();
@@ -187,8 +202,10 @@
     room: appFlow.room,
     myId: appFlow.myId,
     gameResult: appFlow.gameResult,
+    playerName: appFlow.playerName,
     joinErrorMessage: getJoinErrorMessage(joinState.joinFailure),
     isJoining: joinState.isJoining,
+    setPlayerName,
     requestJoin,
     returnToTitle,
   };
diff --git a/apps/client/src/scenes/title/TitleScene.tsx b/apps/client/src/scenes/title/TitleScene.tsx
index ac9c199..53f2cce 100644
--- a/apps/client/src/scenes/title/TitleScene.tsx
+++ b/apps/client/src/scenes/title/TitleScene.tsx
@@ -5,18 +5,26 @@
 type Props = {
   // 入室実行時呼び出しコールバック
   onJoin: (payload: domain.room.JoinRoomPayload) => void;
+  // プレイヤー名の入力値
+  playerName: string;
+  // プレイヤー名の更新コールバック
+  onPlayerNameChange: (value: string) => void;
   // 入室失敗時の表示メッセージ
   joinErrorMessage: string | null;
   // 入室リクエスト送信中フラグ
   isJoining: boolean;
 };
 
-export const TitleScene = ({ onJoin, joinErrorMessage, isJoining }: Props) => {
+export const TitleScene = ({
+  onJoin,
+  playerName,
+  onPlayerNameChange,
+  joinErrorMessage,
+  isJoining,
+}: Props) => {
   // 🌟 追加：「TAP TO START」が押されてフォームを表示する状態かどうか
   const [showForm, setShowForm] = useState(false);
 
-  // プレイヤー名入力値
-  const [playerName, setPlayerName] = useState("");
   // ルームID入力値
   const [roomIdInput, setRoomIdInput] = useState("");
 
@@ -112,7 +120,7 @@
               <input
                 placeholder="プレイヤー名を入力"
                 value={playerName}
-                onChange={(e) => setPlayerName(e.target.value)}
+                onChange={(e) => onPlayerNameChange(e.target.value)}
                 style={{
                   padding: "12px",
                   fontSize: "clamp(1rem, 3vw, 1.2rem)",