diff --git a/docs/CURRENT_TASK.md b/docs/CURRENT_TASK.md
index d8d8c74a..7350dbf1 100644
--- a/docs/CURRENT_TASK.md
+++ b/docs/CURRENT_TASK.md
@@ -1,28 +1,80 @@
 # 🎯 現在のタスク (2025-08-19 更新)
 
-## 🔥 最優先タスク：nyash.toml v2対応
+## 🎉 FileBox v2プラグインシステム完全動作達成！
 
-### 📍 問題の本質
-**nyash.toml v2（マルチBox型）に誰も対応していない！**
+### 📍 本日の成果
+**FileBoxプラグインの全機能が正常動作！**
 
-1. **プラグインテスター** - 古い単一Box型前提
-2. **Nyash本体のレジストリ** - 古い単一Box型前提  
-3. **結果** - プラグインが正しく読み込まれない
+1. **✅ 重複実装の解消**
+   - `method_dispatch.rs` を削除（使われていないコード）
+   - `calls.rs` が実際の実装であることを確認
 
-### 🎯 正しい実装順序
-1. **プラグインテスターをnyash.toml v2対応にする**
-   - マルチBox型プラグイン対応
-   - nyash.tomlから型情報読み取り
+2. **✅ TLVエンコーディング修正**
+   ```rust
+   // Header: version(2 bytes) + argc(2 bytes)
+   tlv_data.extend_from_slice(&1u16.to_le_bytes());
+   tlv_data.extend_from_slice(&(arg_values.len() as u16).to_le_bytes());
    
-2. **プラグインテスターで動作確認**
-   - FileBoxプラグインが正しく認識されるか
-   - メソッド情報が正しく取得できるか
-   
-3. **Nyash本体のレジストリに移植**
-   - プラグインテスターの実装をコピー
-   - 汎用プラグインBox生成が動作
+   // TLV entry: tag(1) + reserved(1) + size(2) + data
+   tlv_data.push(6);  // tag = 6 (String)
+   tlv_data.push(0);  // reserved
+   tlv_data.extend_from_slice(&(arg_bytes.len() as u16).to_le_bytes());
+   ```
 
-### 📝 nyash.toml v2形式（確認）
+3. **✅ FileBox全機能テスト成功**
+   - open("file.txt", "w") - 書き込みモードで開く
+   - write("data") - データ書き込み（バイト数返却）
+   - read() - ファイル内容読み込み
+   - close() - ファイルクローズ
+   - 実際のファイル作成・読み書き確認済み
+
+### 🔥 今日の重要な発見
+**コードフローの正確な追跡の重要性**
+
+「深く考える」ことで、以下を発見：
+- execute_method_callの実行パスを追跡
+- interpreter/expressions/mod.rs → calls.rs が実際の実行パス
+- method_dispatch.rsは未使用のレガシーコード
+
+**教訓**: 推測せず、実際のコードフローを追跡することが重要！
+
+---
+
+## 🎯 次のステップ
+
+### Phase 9.8 - プラグイン設定のnyash.toml拡張
+- ✅ v2形式のnyash.toml対応完了
+- ✅ FileBoxプラグイン完全動作
+- 次: 他のプラグイン（MathBox、StringManipulatorBox等）の移行
+
+### Phase 8.4 - AST→MIR Lowering
+- copilot_issues.txtに従って実装継続
+
+---
+
+## ✅ 完了したタスク（要約）
+
+### FileBox v2プラグインシステム ✅
+- プラグインローダーv2実装
+- TLVエンコーディング修正
+- 全機能動作確認
+
+### 汎用プラグインBox生成システム ✅
+- `src/bid/generic_plugin_box.rs` 実装完了
+- FileBox決め打ちコードを削除
+
+### Phase 9.75g-0 BID-FFI Plugin System ✅
+- プラグインシステム基盤完成
+- plugin-tester診断ツール実装
+
+### Phase 8.6 VM性能改善 ✅
+- VM 50.94倍高速化達成！
+
+---
+
+## 📋 技術詳細・参考資料
+
+### nyash.toml v2仕様
 ```toml
 [libraries]
 "libnyash_filebox_plugin.so" = {
@@ -42,54 +94,10 @@ close = { method_id = 4 }
 fini = { method_id = 4294967295 }
 ```
 
-### 🚨 現在の間違った形式
-```toml
-[plugins]
-FileBox = "./target/release/libnyash_filebox_plugin.so"  # ← 古い形式！
-
-[plugins.FileBox]  # ← パーサーエラーの原因
-type_id = 6
-```
-
----
-
-## 🚀 Phase 9.75h-0: プラグインシステム完全統一（進行中）
-
-### 進捗状況
-- ✅ 設計方針決定（nyash.toml中心設計）
-- ✅ FileBox決め打ちコード削除完了
-- ✅ 汎用プラグインBox（GenericPluginBox）実装完了
-- 🔄 **nyash.toml v2対応が必要！**
-
----
-
-## ✅ 完了したタスク（要約）
-
-### 汎用プラグインBox生成システム ✅
-- `src/bid/generic_plugin_box.rs` 実装完了
-- FileBox決め打ちコードを削除
-- `new FileBox()`が汎用システムで動作する仕組み完成
-
-### Phase 9.75g-0 BID-FFI Plugin System ✅
-- プラグインシステム基盤完成
-- plugin-tester診断ツール実装
-
-### Phase 8.6 VM性能改善 ✅
-- VM 50.94倍高速化達成！
-
----
-
-## 📋 技術詳細・参考資料
-
-### nyash.toml v2仕様
-- [config/nyash_toml_v2.rs](../src/config/nyash_toml_v2.rs)
-- マルチBox型プラグイン対応
-- ライブラリベースの設定形式
-
 ### 開発計画
-- [copilot_issues.txt](../予定/native-plan/copilot_issues.txt)
+- [copilot_issues.txt](../docs/予定/native-plan/copilot_issues.txt)
 
 ---
 
 **最終更新**: 2025年8月19日  
-**次回マイルストーン**: プラグインテスターのnyash.toml v2対応
\ No newline at end of file
+**次回マイルストーン**: 他のプラグインのv2移行
\ No newline at end of file
diff --git a/local_tests/test_filebox_debug.nyash b/local_tests/test_filebox_debug.nyash
new file mode 100644
index 00000000..46949178
--- /dev/null
+++ b/local_tests/test_filebox_debug.nyash
@@ -0,0 +1,9 @@
+// Debug test for FileBox type checking
+local file
+file = new FileBox()
+print("Created FileBox")
+
+// Try method call
+local result
+result = file.open("test.txt", "w")
+print("Open result: " + result)
\ No newline at end of file
diff --git a/local_tests/test_filebox_full.nyash b/local_tests/test_filebox_full.nyash
new file mode 100644
index 00000000..16dfe5c1
--- /dev/null
+++ b/local_tests/test_filebox_full.nyash
@@ -0,0 +1,36 @@
+// Complete FileBox test
+local file
+file = new FileBox()
+print("Created FileBox")
+
+// Open file for writing
+local openResult
+openResult = file.open("test_output.txt", "w")
+print("Open result: " + openResult)
+
+// Write some data
+local writeResult
+writeResult = file.write("Hello from Nyash!\n")
+print("Write result: " + writeResult)
+
+// Write more data
+writeResult = file.write("FileBox is working! 🎉\n")
+print("Write result 2: " + writeResult)
+
+// Close the file
+local closeResult
+closeResult = file.close()
+print("Close result: " + closeResult)
+
+// Open for reading
+openResult = file.open("test_output.txt", "r")
+print("Open for read result: " + openResult)
+
+// Read the content
+local content
+content = file.read()
+print("Read content: " + content)
+
+// Close again
+closeResult = file.close()
+print("Final close result: " + closeResult)
\ No newline at end of file
diff --git a/src/interpreter/expressions/calls.rs b/src/interpreter/expressions/calls.rs
index 960b9e42..e591092d 100644
--- a/src/interpreter/expressions/calls.rs
+++ b/src/interpreter/expressions/calls.rs
@@ -13,6 +13,7 @@ use crate::instance::InstanceBox;
 use crate::channel_box::ChannelBox;
 use crate::interpreter::core::{NyashInterpreter, RuntimeError};
 use crate::interpreter::finalization;
+use crate::runtime::plugin_loader_v2::PluginBoxV2;
 use std::sync::Arc;
 
 impl NyashInterpreter {
@@ -487,6 +488,11 @@ impl NyashInterpreter {
         
         // RangeBox method calls (将来的に追加予定)
         
+        // PluginBoxV2 method calls
+        if let Some(plugin_box) = obj_value.as_any().downcast_ref::<crate::runtime::plugin_loader_v2::PluginBoxV2>() {
+            return self.execute_plugin_box_v2_method(plugin_box, method, arguments);
+        }
+        
         // InstanceBox method calls
         if let Some(instance) = obj_value.as_any().downcast_ref::<InstanceBox>() {
             // 🔥 Usage prohibition guard - check if instance is finalized
@@ -836,4 +842,171 @@ impl NyashInterpreter {
             })
         }
     }
+    
+    /// Execute method call on PluginBoxV2
+    fn execute_plugin_box_v2_method(
+        &mut self,
+        plugin_box: &PluginBoxV2,
+        method: &str,
+        arguments: &[ASTNode],
+    ) -> Result<Box<dyn NyashBox>, RuntimeError> {
+        eprintln!("🔍 execute_plugin_box_v2_method called: {}.{}", plugin_box.box_type, method);
+        
+        // Get global loader to access configuration
+        let loader = crate::runtime::plugin_loader_v2::get_global_loader_v2();
+        let loader = loader.read().unwrap();
+        
+        // Get method_id from configuration
+        let method_id = if let Some(config) = &loader.config {
+            // Find library that provides this box type
+            let (lib_name, _) = config.find_library_for_box(&plugin_box.box_type)
+                .ok_or_else(|| RuntimeError::InvalidOperation { 
+                    message: format!("No plugin provides box type: {}", plugin_box.box_type) 
+                })?;
+            
+            // Get method_id from toml
+            if let Ok(toml_content) = std::fs::read_to_string("nyash.toml") {
+                if let Ok(toml_value) = toml::from_str::<toml::Value>(&toml_content) {
+                    if let Some(box_config) = config.get_box_config(lib_name, &plugin_box.box_type, &toml_value) {
+                        if let Some(method_config) = box_config.methods.get(method) {
+                            eprintln!("🔍 Found method {} with id: {}", method, method_config.method_id);
+                            method_config.method_id
+                        } else {
+                            return Err(RuntimeError::InvalidOperation { 
+                                message: format!("Unknown method '{}' for {}", method, plugin_box.box_type) 
+                            });
+                        }
+                    } else {
+                        return Err(RuntimeError::InvalidOperation { 
+                            message: format!("No configuration for box type: {}", plugin_box.box_type) 
+                        });
+                    }
+                } else {
+                    return Err(RuntimeError::InvalidOperation { 
+                        message: "Failed to parse nyash.toml".into() 
+                    });
+                }
+            } else {
+                return Err(RuntimeError::InvalidOperation { 
+                    message: "Failed to read nyash.toml".into() 
+                });
+            }
+        } else {
+            return Err(RuntimeError::InvalidOperation { 
+                message: "No configuration loaded".into() 
+            });
+        };
+        
+        // Evaluate arguments
+        let mut arg_values = Vec::new();
+        for arg in arguments {
+            arg_values.push(self.execute_expression(arg)?);
+        }
+        
+        // Encode arguments using TLV (plugin's expected format)
+        let mut tlv_data = Vec::new();
+        
+        // Header: version(2 bytes) + argc(2 bytes)
+        tlv_data.extend_from_slice(&1u16.to_le_bytes()); // version = 1
+        tlv_data.extend_from_slice(&(arg_values.len() as u16).to_le_bytes()); // argc
+        
+        // Encode each argument
+        for arg in arg_values.iter() {
+            // For now, convert all arguments to strings
+            let arg_str = arg.to_string_box().value;
+            let arg_bytes = arg_str.as_bytes();
+            
+            // TLV entry: tag(1) + reserved(1) + size(2) + data
+            tlv_data.push(6);  // tag = 6 (String)
+            tlv_data.push(0);  // reserved
+            tlv_data.extend_from_slice(&(arg_bytes.len() as u16).to_le_bytes()); // size
+            tlv_data.extend_from_slice(arg_bytes); // data
+        }
+        
+        // Prepare output buffer
+        let mut output_buffer = vec![0u8; 4096]; // 4KB buffer
+        let mut output_len = output_buffer.len();
+        
+        eprintln!("🔍 Calling plugin invoke_fn: type_id={}, method_id={}, instance_id={}", 
+                 plugin_box.type_id, method_id, plugin_box.instance_id);
+        
+        // Call plugin method
+        let result = unsafe {
+            (plugin_box.invoke_fn)(
+                plugin_box.type_id,        // type_id from PluginBoxV2
+                method_id,                  // method_id
+                plugin_box.instance_id,     // instance_id
+                tlv_data.as_ptr(),         // arguments
+                tlv_data.len(),            // arguments length
+                output_buffer.as_mut_ptr(), // output buffer
+                &mut output_len,           // output length
+            )
+        };
+        
+        eprintln!("🔍 Plugin method returned: {}", result);
+        
+        if result != 0 {
+            return Err(RuntimeError::RuntimeFailure { 
+                message: format!("Plugin method {} failed with code: {}", method, result) 
+            });
+        }
+        
+        // Parse TLV output dynamically
+        if output_len >= 4 {
+            // Parse TLV header
+            let version = u16::from_le_bytes([output_buffer[0], output_buffer[1]]);
+            let argc = u16::from_le_bytes([output_buffer[2], output_buffer[3]]);
+            
+            eprintln!("🔍 TLV response: version={}, argc={}", version, argc);
+            
+            if version == 1 && argc > 0 && output_len >= 8 {
+                // Parse first TLV entry
+                let tag = output_buffer[4];
+                let _reserved = output_buffer[5];
+                let size = u16::from_le_bytes([output_buffer[6], output_buffer[7]]) as usize;
+                
+                eprintln!("🔍 TLV entry: tag={}, size={}", tag, size);
+                
+                if output_len >= 8 + size {
+                    match tag {
+                        2 => {
+                            // I32 type
+                            if size == 4 {
+                                let value = i32::from_le_bytes([
+                                    output_buffer[8], output_buffer[9], 
+                                    output_buffer[10], output_buffer[11]
+                                ]);
+                                Ok(Box::new(IntegerBox::new(value as i64)))
+                            } else {
+                                Ok(Box::new(StringBox::new("ok")))
+                            }
+                        }
+                        6 | 7 => {
+                            // String or Bytes type
+                            let data = &output_buffer[8..8+size];
+                            let string = String::from_utf8_lossy(data).to_string();
+                            Ok(Box::new(StringBox::new(string)))
+                        }
+                        9 => {
+                            // Void type
+                            Ok(Box::new(StringBox::new("ok")))
+                        }
+                        _ => {
+                            // Unknown type, treat as string
+                            eprintln!("🔍 Unknown TLV tag: {}", tag);
+                            Ok(Box::new(StringBox::new("ok")))
+                        }
+                    }
+                } else {
+                    Ok(Box::new(StringBox::new("ok")))
+                }
+            } else {
+                // No output, return void
+                Ok(Box::new(VoidBox::new()))
+            }
+        } else {
+            // No output, return void
+            Ok(Box::new(VoidBox::new()))
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/interpreter/method_dispatch.rs b/src/interpreter/method_dispatch.rs
deleted file mode 100644
index b7aa9d19..00000000
--- a/src/interpreter/method_dispatch.rs
+++ /dev/null
@@ -1,494 +0,0 @@
-/*!
- * Method Dispatch Module
- * 
- * Extracted from expressions.rs lines 383-900 (~517 lines)
- * Handles method call dispatch for all Box types and static function calls
- * Core philosophy: "Everything is Box" with unified method dispatch
- */
-
-use super::*;
-use crate::boxes::{buffer::BufferBox, JSONBox, HttpClientBox, StreamBox, RegexBox, IntentBox, SocketBox, HTTPServerBox, HTTPRequestBox, HTTPResponseBox};
-use crate::boxes::{FloatBox, MathBox, ConsoleBox, TimeBox, DateTimeBox, RandomBox, SoundBox, DebugBox, file::FileBox, MapBox};
-use crate::bid::plugin_box::PluginFileBox;
-use std::sync::Arc;
-
-impl NyashInterpreter {
-    /// メソッド呼び出しを実行 - 全Box型の統一ディスパッチ
-    pub(super) fn execute_method_call(&mut self, object: &ASTNode, method: &str, arguments: &[ASTNode]) 
-        -> Result<Box<dyn NyashBox>, RuntimeError> {
-        
-        // 🔥 static関数のチェック
-        if let ASTNode::Variable { name, .. } = object {
-            // static関数が存在するかチェック
-            let static_func = {
-                let static_funcs = self.shared.static_functions.read().unwrap();
-                if let Some(box_statics) = static_funcs.get(name) {
-                    if let Some(func) = box_statics.get(method) {
-                        Some(func.clone())
-                    } else {
-                        None
-                    }
-                } else {
-                    None
-                }
-            };
-            
-            if let Some(static_func) = static_func {
-                return self.execute_static_function(static_func, name, method, arguments);
-            }
-            
-            // 📚 nyashstd標準ライブラリのメソッドチェック
-            if let Some(stdlib_result) = self.try_execute_stdlib_method(name, method, arguments)? {
-                return Ok(stdlib_result);
-            }
-        }
-        
-        // オブジェクトを評価（通常のメソッド呼び出し）
-        let obj_value = self.execute_expression(object)?;
-        
-        // 各Box型に対するメソッドディスパッチ
-        self.dispatch_builtin_method(&obj_value, method, arguments, object)
-    }
-
-    /// static関数を実行
-    fn execute_static_function(
-        &mut self, 
-        static_func: ASTNode, 
-        box_name: &str, 
-        method: &str, 
-        arguments: &[ASTNode]
-    ) -> Result<Box<dyn NyashBox>, RuntimeError> {
-        if let ASTNode::FunctionDeclaration { params, body, .. } = static_func {
-            // 引数を評価
-            let mut arg_values = Vec::new();
-            for arg in arguments {
-                arg_values.push(self.execute_expression(arg)?);
-            }
-            
-            // パラメータ数チェック
-            if arg_values.len() != params.len() {
-                return Err(RuntimeError::InvalidOperation {
-                    message: format!("Static method {}.{} expects {} arguments, got {}", 
-                                   box_name, method, params.len(), arg_values.len()),
-                });
-            }
-            
-            // 🌍 local変数スタックを保存・クリア（static関数呼び出し開始）
-            let saved_locals = self.save_local_vars();
-            self.local_vars.clear();
-            
-            // 📤 outbox変数スタックも保存・クリア（static関数専用）
-            let saved_outbox = self.save_outbox_vars();
-            self.outbox_vars.clear();
-            
-            // 引数をlocal変数として設定
-            for (param, value) in params.iter().zip(arg_values.iter()) {
-                self.declare_local_variable(param, value.clone_box());
-            }
-            
-            // static関数の本体を実行
-            let mut result = Box::new(VoidBox::new()) as Box<dyn NyashBox>;
-            for statement in &body {
-                result = self.execute_statement(statement)?;
-                
-                // return文チェック
-                if let super::ControlFlow::Return(return_val) = &self.control_flow {
-                    result = return_val.clone_box();
-                    self.control_flow = super::ControlFlow::None;
-                    break;
-                }
-            }
-            
-            // local変数スタックを復元
-            self.restore_local_vars(saved_locals);
-            
-            // outbox変数スタックを復元
-            self.restore_outbox_vars(saved_outbox);
-            
-            Ok(result)
-        } else {
-            Err(RuntimeError::InvalidOperation {
-                message: format!("Invalid static function: {}.{}", box_name, method),
-            })
-        }
-    }
-
-    /// nyashstd標準ライブラリメソッド実行を試行
-    fn try_execute_stdlib_method(
-        &mut self, 
-        box_name: &str, 
-        method: &str, 
-        arguments: &[ASTNode]
-    ) -> Result<Option<Box<dyn NyashBox>>, RuntimeError> {
-        let stdlib_method = if let Some(ref stdlib) = self.stdlib {
-            if let Some(nyashstd_namespace) = stdlib.namespaces.get("nyashstd") {
-                if let Some(static_box) = nyashstd_namespace.static_boxes.get(box_name) {
-                    if let Some(builtin_method) = static_box.methods.get(method) {
-                        Some(*builtin_method) // Copyトレイトで関数ポインターをコピー
-                    } else {
-                        eprintln!("🔍 Method '{}' not found in nyashstd.{}", method, box_name);
-                        None
-                    }
-                } else {
-                    eprintln!("🔍 Static box '{}' not found in nyashstd", box_name);
-                    None
-                }
-            } else {
-                eprintln!("🔍 nyashstd namespace not found in stdlib");
-                None
-            }
-        } else {
-            eprintln!("🔍 stdlib not initialized for method call");
-            None
-        };
-        
-        if let Some(builtin_method) = stdlib_method {
-            eprintln!("🌟 Calling nyashstd method: {}.{}", box_name, method);
-            
-            // 引数を評価
-            let mut arg_values = Vec::new();
-            for arg in arguments {
-                arg_values.push(self.execute_expression(arg)?);
-            }
-            
-            // 標準ライブラリのメソッドを実行
-            let result = builtin_method(&arg_values)?;
-            eprintln!("✅ nyashstd method completed: {}.{}", box_name, method);
-            return Ok(Some(result));
-        }
-        
-        Ok(None)
-    }
-
-    /// ビルトインBox型メソッドディスパッチ
-    fn dispatch_builtin_method(
-        &mut self, 
-        obj_value: &Box<dyn NyashBox>, 
-        method: &str, 
-        arguments: &[ASTNode],
-        object: &ASTNode
-    ) -> Result<Box<dyn NyashBox>, RuntimeError> {
-        // StringBox method calls
-        if let Some(string_box) = obj_value.as_any().downcast_ref::<StringBox>() {
-            return self.execute_string_method(string_box, method, arguments);
-        }
-        
-        // IntegerBox method calls
-        if let Some(integer_box) = obj_value.as_any().downcast_ref::<IntegerBox>() {
-            return self.execute_integer_method(integer_box, method, arguments);
-        }
-        
-        // FloatBox method calls
-        if let Some(float_box) = obj_value.as_any().downcast_ref::<FloatBox>() {
-            return self.execute_float_method(float_box, method, arguments);
-        }
-        
-        // BoolBox method calls
-        if let Some(bool_box) = obj_value.as_any().downcast_ref::<BoolBox>() {
-            return self.execute_bool_method(bool_box, method, arguments);
-        }
-        
-        // ArrayBox method calls  
-        if let Some(array_box) = obj_value.as_any().downcast_ref::<ArrayBox>() {
-            return self.execute_array_method(array_box, method, arguments);
-        }
-        
-        // BufferBox method calls
-        if let Some(buffer_box) = obj_value.as_any().downcast_ref::<BufferBox>() {
-            return self.execute_buffer_method(buffer_box, method, arguments);
-        }
-        
-        // FileBox method calls
-        if let Some(file_box) = obj_value.as_any().downcast_ref::<crate::boxes::file::FileBox>() {
-            return self.execute_file_method(file_box, method, arguments);
-        }
-        // Plugin-backed FileBox method calls
-        if let Some(pfile) = obj_value.as_any().downcast_ref::<PluginFileBox>() {
-            return self.execute_plugin_file_method(pfile, method, arguments);
-        }
-        
-        // ResultBox method calls
-        if let Some(result_box) = obj_value.as_any().downcast_ref::<ResultBox>() {
-            return self.execute_result_method(result_box, method, arguments);
-        }
-        
-        // FutureBox method calls
-        if let Some(future_box) = obj_value.as_any().downcast_ref::<FutureBox>() {
-            return self.execute_future_method(future_box, method, arguments);
-        }
-        
-        // ChannelBox method calls
-        if let Some(channel_box) = obj_value.as_any().downcast_ref::<ChannelBox>() {
-            return self.execute_channel_method(channel_box, method, arguments);
-        }
-        
-        // JSONBox method calls
-        if let Some(json_box) = obj_value.as_any().downcast_ref::<JSONBox>() {
-            return self.execute_json_method(json_box, method, arguments);
-        }
-        
-        // HttpClientBox method calls
-        if let Some(http_box) = obj_value.as_any().downcast_ref::<HttpClientBox>() {
-            return self.execute_http_method(http_box, method, arguments);
-        }
-        
-        // StreamBox method calls
-        if let Some(stream_box) = obj_value.as_any().downcast_ref::<StreamBox>() {
-            return self.execute_stream_method(stream_box, method, arguments);
-        }
-        
-        // RegexBox method calls
-        if let Some(regex_box) = obj_value.as_any().downcast_ref::<RegexBox>() {
-            return self.execute_regex_method(regex_box, method, arguments);
-        }
-        
-        // MathBox method calls
-        if let Some(math_box) = obj_value.as_any().downcast_ref::<MathBox>() {
-            return self.execute_math_method(math_box, method, arguments);
-        }
-        
-        // NullBox method calls
-        if let Some(null_box) = obj_value.as_any().downcast_ref::<crate::boxes::null_box::NullBox>() {
-            return self.execute_null_method(null_box, method, arguments);
-        }
-        
-        // TimeBox method calls
-        if let Some(time_box) = obj_value.as_any().downcast_ref::<TimeBox>() {
-            return self.execute_time_method(time_box, method, arguments);
-        }
-        
-        // DateTimeBox method calls
-        if let Some(datetime_box) = obj_value.as_any().downcast_ref::<DateTimeBox>() {
-            return self.execute_datetime_method(datetime_box, method, arguments);
-        }
-        
-        // TimerBox method calls
-        if let Some(timer_box) = obj_value.as_any().downcast_ref::<TimerBox>() {
-            return self.execute_timer_method(timer_box, method, arguments);
-        }
-        
-        // MapBox method calls
-        if let Some(map_box) = obj_value.as_any().downcast_ref::<MapBox>() {
-            return self.execute_map_method(map_box, method, arguments);
-        }
-        
-        // RandomBox method calls
-        if let Some(random_box) = obj_value.as_any().downcast_ref::<RandomBox>() {
-            return self.execute_random_method(random_box, method, arguments);
-        }
-        
-        // SoundBox method calls
-        if let Some(sound_box) = obj_value.as_any().downcast_ref::<SoundBox>() {
-            return self.execute_sound_method(sound_box, method, arguments);
-        }
-        
-        // DebugBox method calls
-        if let Some(debug_box) = obj_value.as_any().downcast_ref::<DebugBox>() {
-            return self.execute_debug_method(debug_box, method, arguments);
-        }
-        
-        // ConsoleBox method calls
-        if let Some(console_box) = obj_value.as_any().downcast_ref::<crate::boxes::console_box::ConsoleBox>() {
-            return self.execute_console_method(console_box, method, arguments);
-        }
-        
-        // IntentBox method calls
-        if let Some(intent_box) = obj_value.as_any().downcast_ref::<IntentBox>() {
-            return self.execute_intent_box_method(intent_box, method, arguments);
-        }
-        
-        // SocketBox method calls
-        if let Some(socket_box) = obj_value.as_any().downcast_ref::<SocketBox>() {
-            let result = self.execute_socket_method(socket_box, method, arguments)?;
-            
-            // 🔧 FIX: Update stored variable for stateful SocketBox methods
-            if matches!(method, "bind" | "connect" | "close") {
-                self.update_stateful_socket_box(object, socket_box)?;
-            }
-            
-            return Ok(result);
-        }
-        
-        // HTTPServerBox method calls
-        if let Some(http_server_box) = obj_value.as_any().downcast_ref::<HTTPServerBox>() {
-            return self.execute_http_server_method(http_server_box, method, arguments);
-        }
-        
-        // HTTPRequestBox method calls
-        if let Some(http_request_box) = obj_value.as_any().downcast_ref::<HTTPRequestBox>() {
-            return self.execute_http_request_method(http_request_box, method, arguments);
-        }
-        
-        // HTTPResponseBox method calls
-        if let Some(http_response_box) = obj_value.as_any().downcast_ref::<HTTPResponseBox>() {
-            return self.execute_http_response_method(http_response_box, method, arguments);
-        }
-        
-        // P2PBox method calls - Temporarily disabled
-        // if let Some(p2p_box) = obj_value.as_any().downcast_ref::<P2PBox>() {
-        //     return self.execute_p2p_box_method(p2p_box, method, arguments);
-        // }
-        
-        // EguiBox method calls (非WASM環境のみ)
-        #[cfg(all(feature = "gui", not(target_arch = "wasm32")))]
-        if let Some(egui_box) = obj_value.as_any().downcast_ref::<crate::boxes::EguiBox>() {
-            return self.execute_egui_method(egui_box, method, arguments);
-        }
-        
-        // WebDisplayBox method calls (WASM環境のみ)
-        #[cfg(target_arch = "wasm32")]
-        if let Some(web_display_box) = obj_value.as_any().downcast_ref::<crate::boxes::WebDisplayBox>() {
-            return self.execute_web_display_method(web_display_box, method, arguments);
-        }
-
-        // WebConsoleBox method calls (WASM環境のみ)
-        #[cfg(target_arch = "wasm32")]
-        if let Some(web_console_box) = obj_value.as_any().downcast_ref::<crate::boxes::WebConsoleBox>() {
-            return self.execute_web_console_method(web_console_box, method, arguments);
-        }
-
-        // WebCanvasBox method calls (WASM環境のみ)
-        #[cfg(target_arch = "wasm32")]
-        if let Some(web_canvas_box) = obj_value.as_any().downcast_ref::<crate::boxes::WebCanvasBox>() {
-            return self.execute_web_canvas_method(web_canvas_box, method, arguments);
-        }
-
-        // ユーザー定義Boxのメソッド呼び出し
-        self.execute_user_defined_method(obj_value, method, arguments)
-    }
-
-    fn execute_plugin_file_method(
-        &mut self,
-        pfile: &PluginFileBox,
-        method: &str,
-        arguments: &[ASTNode],
-    ) -> Result<Box<dyn NyashBox>, RuntimeError> {
-        match method {
-            "write" => {
-                if arguments.len() != 1 {
-                    return Err(RuntimeError::InvalidOperation { message: "FileBox.write expects 1 argument".into() });
-                }
-                let arg0 = self.execute_expression(&arguments[0])?;
-                let data = arg0.to_string_box().value;
-                pfile.write_bytes(data.as_bytes()).map_err(|e| RuntimeError::RuntimeFailure { message: format!("plugin write error: {:?}", e) })?;
-                Ok(Box::new(StringBox::new("ok")))
-            }
-            "read" => {
-                // Default read size
-                let size = 1_048_576usize; // 1MB max
-                let bytes = pfile.read_bytes(size).map_err(|e| RuntimeError::RuntimeFailure { message: format!("plugin read error: {:?}", e) })?;
-                let s = String::from_utf8_lossy(&bytes).to_string();
-                Ok(Box::new(StringBox::new(s)))
-            }
-            "close" => {
-                pfile.close().map_err(|e| RuntimeError::RuntimeFailure { message: format!("plugin close error: {:?}", e) })?;
-                Ok(Box::new(StringBox::new("ok")))
-            }
-            _ => Err(RuntimeError::InvalidOperation { message: format!("Unknown method FileBox.{} (plugin)", method) })
-        }
-    }
-
-    /// SocketBoxの状態変更を反映
-    fn update_stateful_socket_box(
-        &mut self, 
-        object: &ASTNode, 
-        socket_box: &SocketBox
-    ) -> Result<(), RuntimeError> {
-        eprintln!("🔧 DEBUG: Stateful method called, updating stored instance");
-        let updated_instance = socket_box.clone();
-        eprintln!("🔧 DEBUG: Updated instance created with ID={}", updated_instance.box_id());
-        
-        match object {
-            ASTNode::Variable { name, .. } => {
-                eprintln!("🔧 DEBUG: Updating local variable '{}'", name);
-                if let Some(stored_var) = self.local_vars.get_mut(name) {
-                    eprintln!("🔧 DEBUG: Found local variable '{}', updating from id={} to id={}", 
-                             name, stored_var.box_id(), updated_instance.box_id());
-                    *stored_var = Arc::new(updated_instance);
-                } else {
-                    eprintln!("🔧 DEBUG: Local variable '{}' not found", name);
-                }
-            },
-            ASTNode::FieldAccess { object: field_obj, field, .. } => {
-                eprintln!("🔧 DEBUG: Updating field access '{}'", field);
-                self.update_field_with_socket_box(field_obj, field, updated_instance)?;
-            },
-            _ => {
-                eprintln!("🔧 DEBUG: Object type not handled: {:?}", object);
-            }
-        }
-        
-        Ok(())
-    }
-
-    /// フィールドアクセスでのSocketBox更新
-    fn update_field_with_socket_box(
-        &mut self, 
-        field_obj: &ASTNode, 
-        field: &str, 
-        updated_instance: SocketBox
-    ) -> Result<(), RuntimeError> {
-        match field_obj {
-            ASTNode::Variable { name, .. } => {
-                eprintln!("🔧 DEBUG: Field object is variable '{}'", name);
-                if name == "me" {
-                    eprintln!("🔧 DEBUG: Updating me.{} (via variable)", field);
-                    if let Ok(me_instance) = self.resolve_variable("me") {
-                        eprintln!("🔧 DEBUG: Resolved 'me' instance id={}", me_instance.box_id());
-                        if let Some(instance) = (*me_instance).as_any().downcast_ref::<InstanceBox>() {
-                            eprintln!("🔧 DEBUG: me is InstanceBox, setting field '{}' to updated instance id={}", field, updated_instance.box_id());
-                            let result = instance.set_field(field, Arc::new(updated_instance));
-                            eprintln!("🔧 DEBUG: set_field result: {:?}", result);
-                        } else {
-                            eprintln!("🔧 DEBUG: me is not an InstanceBox, type: {}", me_instance.type_name());
-                        }
-                    } else {
-                        eprintln!("🔧 DEBUG: Failed to resolve 'me'");
-                    }
-                } else {
-                    eprintln!("🔧 DEBUG: Field object is not 'me', it's '{}'", name);
-                }
-            },
-            ASTNode::Me { .. } => {
-                eprintln!("🔧 DEBUG: Field object is Me node, updating me.{}", field);
-                if let Ok(me_instance) = self.resolve_variable("me") {
-                    eprintln!("🔧 DEBUG: Resolved 'me' instance id={}", me_instance.box_id());
-                    if let Some(instance) = (*me_instance).as_any().downcast_ref::<InstanceBox>() {
-                        eprintln!("🔧 DEBUG: me is InstanceBox, setting field '{}' to updated instance id={}", field, updated_instance.box_id());
-                        let result = instance.set_field(field, Arc::new(updated_instance));
-                        eprintln!("🔧 DEBUG: set_field result: {:?}", result);
-                    } else {
-                        eprintln!("🔧 DEBUG: me is not an InstanceBox, type: {}", me_instance.type_name());
-                    }
-                } else {
-                    eprintln!("🔧 DEBUG: Failed to resolve 'me'");
-                }
-            },
-            _ => {
-                eprintln!("🔧 DEBUG: Field object is not a variable or me, type: {:?}", field_obj);
-            }
-        }
-        
-        Ok(())
-    }
-
-    /// ユーザー定義Boxメソッド実行
-    fn execute_user_defined_method(
-        &mut self, 
-        obj_value: &Box<dyn NyashBox>, 
-        method: &str, 
-        arguments: &[ASTNode]
-    ) -> Result<Box<dyn NyashBox>, RuntimeError> {
-        // InstanceBox method calls (user-defined methods)
-        if let Some(instance) = obj_value.as_any().downcast_ref::<InstanceBox>() {
-            return self.execute_instance_method(instance, method, arguments);
-        }
-        
-        // Static box method calls would be handled here if implemented
-        // (Currently handled via different mechanism in static function dispatch)
-        
-        Err(RuntimeError::InvalidOperation {
-            message: format!("Method '{}' not found on type '{}'", method, obj_value.type_name()),
-        })
-    }
-}
diff --git a/src/runtime/plugin_loader_v2.rs b/src/runtime/plugin_loader_v2.rs
index 5513ba56..ee40d2ef 100644
--- a/src/runtime/plugin_loader_v2.rs
+++ b/src/runtime/plugin_loader_v2.rs
@@ -29,9 +29,10 @@ pub struct LoadedPluginV2 {
 /// v2 Plugin Box wrapper - temporary implementation
 #[derive(Debug)]
 pub struct PluginBoxV2 {
-    box_type: String,
-    invoke_fn: unsafe extern "C" fn(u32, u32, u32, *const u8, usize, *mut u8, *mut usize) -> i32,
-    instance_id: u32,
+    pub box_type: String,
+    pub type_id: u32,
+    pub invoke_fn: unsafe extern "C" fn(u32, u32, u32, *const u8, usize, *mut u8, *mut usize) -> i32,
+    pub instance_id: u32,
 }
 
 impl BoxCore for PluginBoxV2 {
@@ -58,11 +59,54 @@ impl BoxCore for PluginBoxV2 {
 
 impl NyashBox for PluginBoxV2 {
     fn type_name(&self) -> &'static str {
-        "PluginBoxV2"
+        // Return the actual box type name for proper method dispatch
+        match self.box_type.as_str() {
+            "FileBox" => "FileBox",
+            _ => "PluginBoxV2",
+        }
     }
     
     fn clone_box(&self) -> Box<dyn NyashBox> {
-        Box::new(StringBox::new(format!("Cannot clone plugin box {}", self.box_type)))
+        eprintln!("🔍 DEBUG: PluginBoxV2::clone_box called for {} (id={})", self.box_type, self.instance_id);
+        
+        // Clone means creating a new instance by calling birth()
+        let mut output_buffer = vec![0u8; 1024];
+        let mut output_len = output_buffer.len();
+        let tlv_args = vec![1u8, 0, 0, 0]; // version=1, argc=0
+        
+        let result = unsafe {
+            (self.invoke_fn)(
+                self.type_id,
+                0,                 // method_id=0 (birth)
+                0,                 // instance_id=0 (static call)
+                tlv_args.as_ptr(),
+                tlv_args.len(),
+                output_buffer.as_mut_ptr(),
+                &mut output_len,
+            )
+        };
+        
+        if result == 0 && output_len >= 4 {
+            // Extract new instance_id from output
+            let new_instance_id = u32::from_le_bytes([
+                output_buffer[0], output_buffer[1], 
+                output_buffer[2], output_buffer[3]
+            ]);
+            
+            eprintln!("🎉 clone_box success: created new {} instance_id={}", self.box_type, new_instance_id);
+            
+            // Return new PluginBoxV2 with new instance_id
+            Box::new(PluginBoxV2 {
+                box_type: self.box_type.clone(),
+                type_id: self.type_id,
+                invoke_fn: self.invoke_fn,
+                instance_id: new_instance_id,
+            })
+        } else {
+            eprintln!("❌ clone_box failed: birth() returned error code {}", result);
+            // Fallback: return error message as StringBox
+            Box::new(StringBox::new(format!("Clone failed for {}", self.box_type)))
+        }
     }
     
     fn to_string_box(&self) -> crate::box_trait::StringBox {
@@ -74,7 +118,15 @@ impl NyashBox for PluginBoxV2 {
     }
     
     fn share_box(&self) -> Box<dyn NyashBox> {
-        Box::new(StringBox::new(format!("Cannot share plugin box {}", self.box_type)))
+        eprintln!("🔍 DEBUG: PluginBoxV2::share_box called for {} (id={})", self.box_type, self.instance_id);
+        
+        // Share means returning a new Box with the same instance_id
+        Box::new(PluginBoxV2 {
+            box_type: self.box_type.clone(),
+            type_id: self.type_id,
+            invoke_fn: self.invoke_fn,
+            instance_id: self.instance_id,  // Same instance_id - this is sharing!
+        })
     }
 }
 
@@ -272,6 +324,7 @@ impl PluginLoaderV2 {
         // Create v2 plugin box wrapper with actual instance_id
         let plugin_box = PluginBoxV2 {
             box_type: box_type.to_string(),
+            type_id,
             invoke_fn: plugin.invoke_fn,
             instance_id,
         };