diff --git a/src/box_trait.rs b/src/box_trait.rs
index c94f247a..84f56136 100644
--- a/src/box_trait.rs
+++ b/src/box_trait.rs
@@ -87,6 +87,9 @@ pub trait NyashBox: BoxCore + Debug {
     /// Clone this box (equivalent to Python's copy())
     fn clone_box(&self) -> Box<dyn NyashBox>;
     
+    /// Share this box (state-preserving reference sharing)
+    fn share_box(&self) -> Box<dyn NyashBox>;
+    
     /// Arc参照を返す新しいcloneメソッド（参照共有）
     fn clone_arc(&self) -> SharedNyashBox {
         Arc::from(self.clone_box())
diff --git a/src/boxes/array/mod.rs b/src/boxes/array/mod.rs
index 8566ea37..63842a9b 100644
--- a/src/boxes/array/mod.rs
+++ b/src/boxes/array/mod.rs
@@ -282,6 +282,11 @@ impl NyashBox for ArrayBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
         Box::new(self.clone())
     }
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
 
     fn to_string_box(&self) -> StringBox {
         let items = self.items.read().unwrap();
diff --git a/src/boxes/audio_box.rs b/src/boxes/audio_box.rs
index b90a5f53..7d8a5bc1 100644
--- a/src/boxes/audio_box.rs
+++ b/src/boxes/audio_box.rs
@@ -304,6 +304,12 @@ impl BoxCore for AudioBox {
 
 impl NyashBox for AudioBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/bool_box.rs b/src/boxes/bool_box.rs
index b6c5b46e..25f2cd7b 100644
--- a/src/boxes/bool_box.rs
+++ b/src/boxes/bool_box.rs
@@ -83,10 +83,17 @@ impl NyashBox for BoolBox {
         "BoolBox"
     }
     
+    
     fn clone_box(&self) -> Box<dyn NyashBox> {
         Box::new(self.clone())
     }
     
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+}
+    
     
 }
 
diff --git a/src/boxes/buffer/mod.rs b/src/boxes/buffer/mod.rs
index 4fa21ec5..d256afe6 100644
--- a/src/boxes/buffer/mod.rs
+++ b/src/boxes/buffer/mod.rs
@@ -193,6 +193,11 @@ impl NyashBox for BufferBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
         Box::new(self.clone())
     }
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
 
     fn to_string_box(&self) -> StringBox {
         let data = self.data.read().unwrap();
diff --git a/src/boxes/canvas_event_box.rs b/src/boxes/canvas_event_box.rs
index 8298dd9f..4095d2f6 100644
--- a/src/boxes/canvas_event_box.rs
+++ b/src/boxes/canvas_event_box.rs
@@ -272,6 +272,12 @@ impl BoxCore for CanvasEventBox {
 
 impl NyashBox for CanvasEventBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/canvas_loop_box.rs b/src/boxes/canvas_loop_box.rs
index 5bda7f1d..3ff1dd2f 100644
--- a/src/boxes/canvas_loop_box.rs
+++ b/src/boxes/canvas_loop_box.rs
@@ -282,6 +282,12 @@ impl BoxCore for CanvasLoopBox {
 
 impl NyashBox for CanvasLoopBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/console_box.rs b/src/boxes/console_box.rs
index 44af28f5..f9131bc1 100644
--- a/src/boxes/console_box.rs
+++ b/src/boxes/console_box.rs
@@ -121,6 +121,12 @@ impl NyashBox for ConsoleBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
@@ -195,6 +201,12 @@ impl NyashBox for ConsoleBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
diff --git a/src/boxes/debug_box.rs b/src/boxes/debug_box.rs
index 9ecfe059..2a6ac757 100644
--- a/src/boxes/debug_box.rs
+++ b/src/boxes/debug_box.rs
@@ -377,6 +377,12 @@ impl NyashBox for DebugBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
diff --git a/src/boxes/egui_box.rs b/src/boxes/egui_box.rs
index b791f6b8..0e42d910 100644
--- a/src/boxes/egui_box.rs
+++ b/src/boxes/egui_box.rs
@@ -154,6 +154,12 @@ impl NyashBox for EguiBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
diff --git a/src/boxes/file/mod.rs b/src/boxes/file/mod.rs
index 98e6ce49..111640f3 100644
--- a/src/boxes/file/mod.rs
+++ b/src/boxes/file/mod.rs
@@ -134,6 +134,12 @@ impl BoxCore for FileBox {
 
 impl NyashBox for FileBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         // Note: Cannot truly clone a File handle, so create a new one to the same path
         match FileBox::open(&self.path) {
             Ok(new_file) => Box::new(new_file),
diff --git a/src/boxes/future/mod.rs b/src/boxes/future/mod.rs
index b817269a..bd916f98 100644
--- a/src/boxes/future/mod.rs
+++ b/src/boxes/future/mod.rs
@@ -73,6 +73,12 @@ impl NyashFutureBox {
 
 impl NyashBox for NyashFutureBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/http/mod.rs b/src/boxes/http/mod.rs
index 3b065a05..0f9966d1 100644
--- a/src/boxes/http/mod.rs
+++ b/src/boxes/http/mod.rs
@@ -49,6 +49,12 @@ impl HttpClientBox {
 
 impl NyashBox for HttpClientBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/http_message_box.rs b/src/boxes/http_message_box.rs
index 1eb1ace8..6b43dbc5 100644
--- a/src/boxes/http_message_box.rs
+++ b/src/boxes/http_message_box.rs
@@ -193,6 +193,12 @@ impl HTTPRequestBox {
 
 impl NyashBox for HTTPRequestBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
@@ -371,6 +377,12 @@ impl HTTPResponseBox {
 
 impl NyashBox for HTTPResponseBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/http_server_box.rs b/src/boxes/http_server_box.rs
index b1b39c87..c282cbb1 100644
--- a/src/boxes/http_server_box.rs
+++ b/src/boxes/http_server_box.rs
@@ -365,6 +365,12 @@ impl HTTPServerBox {
 
 impl NyashBox for HTTPServerBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/integer_box.rs b/src/boxes/integer_box.rs
index f1a9c44f..5090acac 100644
--- a/src/boxes/integer_box.rs
+++ b/src/boxes/integer_box.rs
@@ -79,10 +79,17 @@ impl NyashBox for IntegerBox {
         "IntegerBox"
     }
     
+    
     fn clone_box(&self) -> Box<dyn NyashBox> {
         Box::new(self.clone())
     }
     
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+}
+    
     
 }
 
diff --git a/src/boxes/intent_box.rs b/src/boxes/intent_box.rs
index f590fbb8..722dbb9d 100644
--- a/src/boxes/intent_box.rs
+++ b/src/boxes/intent_box.rs
@@ -97,6 +97,12 @@ impl IntentBox {
 
 impl NyashBox for IntentBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/json/mod.rs b/src/boxes/json/mod.rs
index 1c789f50..4500ee46 100644
--- a/src/boxes/json/mod.rs
+++ b/src/boxes/json/mod.rs
@@ -173,6 +173,12 @@ impl std::fmt::Display for JSONBox {
 
 impl NyashBox for JSONBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/map_box.rs b/src/boxes/map_box.rs
index d2e31be0..974330f8 100644
--- a/src/boxes/map_box.rs
+++ b/src/boxes/map_box.rs
@@ -269,10 +269,17 @@ impl NyashBox for MapBox {
         StringBox::new(&format!("MapBox(size={})", size))
     }
     
+    
     fn clone_box(&self) -> Box<dyn NyashBox> {
         Box::new(self.clone())
     }
     
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+}
+    
     fn equals(&self, other: &dyn NyashBox) -> BoolBox {
         if let Some(other_map) = other.as_any().downcast_ref::<MapBox>() {
             // 同じインスタンスかチェック（データの共有を考慮）
diff --git a/src/boxes/math_box.rs b/src/boxes/math_box.rs
index 764285db..25d451a6 100644
--- a/src/boxes/math_box.rs
+++ b/src/boxes/math_box.rs
@@ -314,6 +314,12 @@ impl NyashBox for MathBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
@@ -381,6 +387,12 @@ impl NyashBox for FloatBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
@@ -474,6 +486,12 @@ impl NyashBox for RangeBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
diff --git a/src/boxes/null_box.rs b/src/boxes/null_box.rs
index 8fc54e7c..9201ddef 100644
--- a/src/boxes/null_box.rs
+++ b/src/boxes/null_box.rs
@@ -166,6 +166,12 @@ impl NyashBox for NullBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
diff --git a/src/boxes/p2p_box.rs b/src/boxes/p2p_box.rs
index dbbf49de..694c95d1 100644
--- a/src/boxes/p2p_box.rs
+++ b/src/boxes/p2p_box.rs
@@ -153,6 +153,12 @@ impl P2PBox {
 
 impl NyashBox for P2PBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/qr_box.rs b/src/boxes/qr_box.rs
index 2f43cd14..129aee8e 100644
--- a/src/boxes/qr_box.rs
+++ b/src/boxes/qr_box.rs
@@ -307,6 +307,12 @@ impl BoxCore for QRBox {
 
 impl NyashBox for QRBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/random_box.rs b/src/boxes/random_box.rs
index 61bb1f2a..97d79050 100644
--- a/src/boxes/random_box.rs
+++ b/src/boxes/random_box.rs
@@ -267,6 +267,12 @@ impl NyashBox for RandomBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
diff --git a/src/boxes/regex/mod.rs b/src/boxes/regex/mod.rs
index 8b186df7..b9e5f066 100644
--- a/src/boxes/regex/mod.rs
+++ b/src/boxes/regex/mod.rs
@@ -83,6 +83,12 @@ impl RegexBox {
 
 impl NyashBox for RegexBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/result/mod.rs b/src/boxes/result/mod.rs
index 7fe7ce6b..c9f12428 100644
--- a/src/boxes/result/mod.rs
+++ b/src/boxes/result/mod.rs
@@ -38,6 +38,12 @@ impl NyashResultBox {
 
 impl NyashBox for NyashResultBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         match self {
             NyashResultBox::Ok(val) => Box::new(NyashResultBox::Ok(val.clone_box())),
             NyashResultBox::Err(err) => Box::new(NyashResultBox::Err(err.clone_box())),
diff --git a/src/boxes/simple_intent_box.rs b/src/boxes/simple_intent_box.rs
index 4452b8c8..68535677 100644
--- a/src/boxes/simple_intent_box.rs
+++ b/src/boxes/simple_intent_box.rs
@@ -231,6 +231,12 @@ impl NyashBox for SimpleIntentBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
diff --git a/src/boxes/socket_box.rs b/src/boxes/socket_box.rs
index 792e4052..6e4066a8 100644
--- a/src/boxes/socket_box.rs
+++ b/src/boxes/socket_box.rs
@@ -384,6 +384,11 @@ impl NyashBox for SocketBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
         Box::new(self.clone())
     }
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
 
     fn to_string_box(&self) -> StringBox {
         eprintln!("🔥 SOCKETBOX to_string_box() called - Socket ID = {}", self.base.id);
diff --git a/src/boxes/sound_box.rs b/src/boxes/sound_box.rs
index dd18fd49..bf728681 100644
--- a/src/boxes/sound_box.rs
+++ b/src/boxes/sound_box.rs
@@ -323,6 +323,12 @@ impl NyashBox for SoundBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
diff --git a/src/boxes/stream/mod.rs b/src/boxes/stream/mod.rs
index c7ae4292..7a7b9788 100644
--- a/src/boxes/stream/mod.rs
+++ b/src/boxes/stream/mod.rs
@@ -137,6 +137,12 @@ impl NyashStreamBox {
 
 impl NyashBox for NyashStreamBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/string_box.rs b/src/boxes/string_box.rs
index da9b74ae..91afa3a7 100644
--- a/src/boxes/string_box.rs
+++ b/src/boxes/string_box.rs
@@ -147,10 +147,17 @@ impl NyashBox for StringBox {
         "StringBox"
     }
     
+    
     fn clone_box(&self) -> Box<dyn NyashBox> {
         Box::new(self.clone())
     }
     
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+}
+    
     
 }
 
diff --git a/src/boxes/time_box.rs b/src/boxes/time_box.rs
index 738239ab..2913dcd1 100644
--- a/src/boxes/time_box.rs
+++ b/src/boxes/time_box.rs
@@ -197,6 +197,12 @@ impl NyashBox for TimeBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
@@ -368,6 +374,12 @@ impl NyashBox for DateTimeBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
@@ -452,6 +464,12 @@ impl NyashBox for TimerBox {
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
     
diff --git a/src/boxes/timer_box.rs b/src/boxes/timer_box.rs
index b0ecb278..92df343b 100644
--- a/src/boxes/timer_box.rs
+++ b/src/boxes/timer_box.rs
@@ -215,6 +215,12 @@ impl BoxCore for TimerBox {
 
 impl NyashBox for TimerBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/web/web_canvas_box.rs b/src/boxes/web/web_canvas_box.rs
index 4fff177a..47469777 100644
--- a/src/boxes/web/web_canvas_box.rs
+++ b/src/boxes/web/web_canvas_box.rs
@@ -284,6 +284,12 @@ impl BoxCore for WebCanvasBox {
 #[cfg(target_arch = "wasm32")]
 impl NyashBox for WebCanvasBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/web/web_console_box.rs b/src/boxes/web/web_console_box.rs
index 041478e6..6e0d9c27 100644
--- a/src/boxes/web/web_console_box.rs
+++ b/src/boxes/web/web_console_box.rs
@@ -161,6 +161,12 @@ impl BoxCore for WebConsoleBox {
 #[cfg(target_arch = "wasm32")]
 impl NyashBox for WebConsoleBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }
 
diff --git a/src/boxes/web/web_display_box.rs b/src/boxes/web/web_display_box.rs
index 13b8c77f..3b24b865 100644
--- a/src/boxes/web/web_display_box.rs
+++ b/src/boxes/web/web_display_box.rs
@@ -154,6 +154,12 @@ impl BoxCore for WebDisplayBox {
 #[cfg(target_arch = "wasm32")]
 impl NyashBox for WebDisplayBox {
     fn clone_box(&self) -> Box<dyn NyashBox> {
+    
+    /// 仮実装: clone_boxと同じ（後で修正）
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
+
         Box::new(self.clone())
     }