diff --git a/Assets/UniGLTF/Editor/AssetMenu.cs b/Assets/UniGLTF/Editor/AssetMenu.cs
new file mode 100644
index 000000000..3bf83de32
--- /dev/null
+++ b/Assets/UniGLTF/Editor/AssetMenu.cs
@@ -0,0 +1,27 @@
+using UnityEditor;
+using UnityEngine;
+
+namespace UniGLTF
+{
+    public static class AssetMenu
+    {
+        [MenuItem("Assets/SaveAsPng", true)]
+        [MenuItem("Assets/SaveAsPngLinear", true)]
+        static bool IsTextureAsset()
+        {
+            return Selection.activeObject is Texture2D;
+        }
+
+        [MenuItem("Assets/SaveAsPng")]
+        static void SaveAsPng()
+        {
+            MeshUtility.EditorChangeTextureType.SaveAsPng(true);
+        }
+
+        [MenuItem("Assets/SaveAsPngLinear")]
+        static void SaveAsPngLinear()
+        {
+            MeshUtility.EditorChangeTextureType.SaveAsPng(false);
+        }
+    }
+}
\ No newline at end of file
diff --git a/Assets/UniGLTF/Editor/AssetMenu.cs.meta b/Assets/UniGLTF/Editor/AssetMenu.cs.meta
new file mode 100644
index 000000000..29afbd7e8
--- /dev/null
+++ b/Assets/UniGLTF/Editor/AssetMenu.cs.meta
@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: ddb68b5016b643edb75db97123f2b6b9
+timeCreated: 1638961746
\ No newline at end of file
diff --git a/Assets/UniGLTF/Editor/TopMenu.cs b/Assets/UniGLTF/Editor/TopMenu.cs
new file mode 100644
index 000000000..285e187ee
--- /dev/null
+++ b/Assets/UniGLTF/Editor/TopMenu.cs
@@ -0,0 +1,69 @@
+using System.IO;
+using UnityEditor;
+using UnityEngine;
+
+namespace UniGLTF
+{
+    /// <summary>
+    /// 機能をどのようにトップメニューに表示するかどうかだけを記述する.
+    /// </summary>
+    public static class TopMenu
+    {
+        private const string UserGltfMenuPrefix = UniGLTFVersion.MENU;
+        private const string UserMeshUtilityPrefix = UniGLTFVersion.MENU + "/Mesh Utility";
+        private const string DevelopmentMenuPrefix = UniGLTFVersion.MENU + "/Development";
+        private const int UserGltfMenuPriority = 0;
+        private const int UserMeshUtilityMenuPriority = 10;
+        private const int DevelopmentMenuPriority = 30;
+
+        #region USER
+        [MenuItem(
+            UserGltfMenuPrefix + "/Version: " + UniGLTFVersion.UNIGLTF_VERSION,
+            validate = true)]
+        private static bool ShowVersionValidation() => false;
+
+        [MenuItem(
+            UserGltfMenuPrefix + "/Version: " + UniGLTFVersion.UNIGLTF_VERSION,
+            priority = UserGltfMenuPriority + 0)]
+        private static void ShowVersion()
+        {
+        }
+
+        [MenuItem(
+            UserGltfMenuPrefix + "/Export to GLB",
+            priority = UserGltfMenuPriority + 1)]
+        private static void ExportGameObjectToGltf() => TopMenuImplementation.ExportGameObjectToGltfFile();
+
+        [MenuItem(
+            UserGltfMenuPrefix + "/Import from GLTF (*.gltf|*.glb|*.zip)",
+            priority = UserGltfMenuPriority + 2)]
+        private static void ImportGltfFile() => TopMenuImplementation.ImportGltfFileToGameObject();
+        #endregion
+
+        #region MESH_UTILITY
+
+        [MenuItem(
+            UserMeshUtilityPrefix + "/MeshProcessing Wizard",
+            priority = UserMeshUtilityMenuPriority + 0)]
+        private static void OpenMeshProcessingWindow() => TopMenuImplementation.OpenMeshProcessingWindow();
+
+        [MenuItem(
+            UserMeshUtilityPrefix + "/Open Documents",
+            priority = UserMeshUtilityMenuPriority + 1)]
+        private static void MeshUtilityDocs() => Application.OpenURL("https://vrm.dev/en/docs/univrm/gltf/mesh_utility/");
+        #endregion
+
+        #region DEVELOPMENT
+        [MenuItem(
+            DevelopmentMenuPrefix + "/Generate Serialization Code",
+            priority = DevelopmentMenuPriority + 1)]
+        private static void GenerateSerializationCode() => TopMenuImplementation.GenerateSerializationCode();
+
+
+        [MenuItem(
+            DevelopmentMenuPrefix + "/Generate UniJSON ConcreteCast",
+            priority = DevelopmentMenuPriority + 2)]
+        private static void GenerateUniJsonConcreteCastCode() => UniJSON.ConcreteCast.GenerateGenericCast();
+        #endregion
+    }
+}
diff --git a/Assets/UniGLTF/Editor/Menu.cs.meta b/Assets/UniGLTF/Editor/TopMenu.cs.meta
similarity index 100%
rename from Assets/UniGLTF/Editor/Menu.cs.meta
rename to Assets/UniGLTF/Editor/TopMenu.cs.meta
diff --git a/Assets/UniGLTF/Editor/Menu.cs b/Assets/UniGLTF/Editor/TopMenuImplementation.cs
similarity index 58%
rename from Assets/UniGLTF/Editor/Menu.cs
rename to Assets/UniGLTF/Editor/TopMenuImplementation.cs
index 3fc3f1fd3..a9ec44f1f 100644
--- a/Assets/UniGLTF/Editor/Menu.cs
+++ b/Assets/UniGLTF/Editor/TopMenuImplementation.cs
@@ -1,17 +1,19 @@
-using System.IO;
+using System.IO;
 using UnityEditor;
 using UnityEngine;
 
 namespace UniGLTF
 {
-    /// <summary>
-    /// Menuは一か所で管理する
-    /// </summary>
-    public static class Menu
+    public static class TopMenuImplementation
     {
-        #region UniGLTF
-        [MenuItem(UniGLTFVersion.MENU + "/Import(gltf, glb, zip)", priority = 1)]
-        public static void ImportMenu()
+        public static void ExportGameObjectToGltfFile()
+        {
+            var window = (GltfExportWindow) GltfExportWindow.GetWindow(typeof(GltfExportWindow));
+            window.titleContent = new GUIContent("Gltf Exporter");
+            window.Show();
+        }
+
+        public static void ImportGltfFileToGameObject()
         {
             var path = EditorUtility.OpenFilePanel("open glb", "", "gltf,glb,zip");
             if (string.IsNullOrEmpty(path))
@@ -90,72 +92,19 @@ namespace UniGLTF
             Selection.activeObject = asset;
         }
 
-        [MenuItem(UniGLTFVersion.MENU + "/Export " + UniGLTFVersion.UNIGLTF_VERSION, false, 0)]
-        private static void ExportFromMenu()
+        public static void OpenMeshProcessingWindow()
         {
-            var window = (GltfExportWindow)GltfExportWindow.GetWindow(typeof(GltfExportWindow));
-            window.titleContent = new GUIContent("Gltf Exporter");
-            window.Show();
-        }
-
-        [MenuItem(UniGLTFVersion.MENU + "/GLTF: Generate Deserializer")]
-        static void GenerateDeserializer()
-        {
-            DeserializerGenerator.GenerateSerializer();
-        }
-
-        [MenuItem(UniGLTFVersion.MENU + "/GLTF: Generate Serializer")]
-        static void GenerateSerializer()
-        {
-            DeserializerGenerator.GenerateSerializer();
-        }
-        #endregion
-
-        #region  MeshUtility
-        // [MenuItem(MeshUtility.MENU_PARENT + "BoneMeshEraser Wizard", priority = 31)]
-        // static void CreateWizard()
-        // {
-        //     ScriptableWizard.DisplayWizard<BoneMeshEraserWizard>("BoneMeshEraser", "Erase triangles by bone", "Erase");
-        // }
-        const string MESH_UTILITY_DICT = "UniGLTF/Mesh Utility/";
-        [MenuItem(MESH_UTILITY_DICT + "MeshProcessing Wizard", priority = 30)]
-        static void MeshProcessFromMenu()
-        {
-            var window = (MeshUtility.MeshProcessDialog)EditorWindow.GetWindowWithRect(typeof(MeshUtility.MeshProcessDialog), new Rect(0, 0, 650, 500));
+            var window =
+                (MeshUtility.MeshProcessDialog) EditorWindow.GetWindowWithRect(typeof(MeshUtility.MeshProcessDialog),
+                    new Rect(0, 0, 650, 500));
             window.titleContent = new GUIContent("Mesh Processing Window");
             window.Show();
         }
 
-        [MenuItem(MESH_UTILITY_DICT + "MeshUtility Docs", priority = 32)]
-        public static void MeshUtilityDocs()
+        public static void GenerateSerializationCode()
         {
-            Application.OpenURL("https://vrm.dev/en/docs/univrm/gltf/mesh_utility/");
-        }
-
-        [MenuItem("Assets/SaveAsPng", true)]
-        [MenuItem("Assets/SaveAsPngLinear", true)]
-        static bool IsTextureAsset()
-        {
-            return Selection.activeObject is Texture2D;
-        }
-
-        [MenuItem("Assets/SaveAsPng")]
-        static void SaveAsPng()
-        {
-            MeshUtility.EditorChangeTextureType.SaveAsPng(true);
-        }
-
-        [MenuItem("Assets/SaveAsPngLinear")]
-        static void SaveAsPngLinear()
-        {
-            MeshUtility.EditorChangeTextureType.SaveAsPng(false);
-        }
-        #endregion
-
-        [MenuItem("UniGLTF/UniJSON/Generate ConcreteCast")]
-        static void GenerateConcreteCast()
-        {
-            UniJSON.ConcreteCast.GenerateGenericCast();
+            SerializerGenerator.GenerateSerializer();
+            DeserializerGenerator.GenerateSerializer();
         }
     }
-}
+}
\ No newline at end of file
diff --git a/Assets/UniGLTF/Editor/TopMenuImplementation.cs.meta b/Assets/UniGLTF/Editor/TopMenuImplementation.cs.meta
new file mode 100644
index 000000000..1024de137
--- /dev/null
+++ b/Assets/UniGLTF/Editor/TopMenuImplementation.cs.meta
@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 173b43f1467d4054921297a5c2e55d05
+timeCreated: 1638961414
\ No newline at end of file
diff --git a/Assets/VRMShaders/VRM/IO/Editor/ShaderPropMenu.cs b/Assets/VRMShaders/VRM/IO/Editor/ShaderPropMenu.cs
index 0d5151696..3a949d10a 100644
--- a/Assets/VRMShaders/VRM/IO/Editor/ShaderPropMenu.cs
+++ b/Assets/VRMShaders/VRM/IO/Editor/ShaderPropMenu.cs
@@ -11,7 +11,7 @@ namespace UniGLTF
     public static class ShaderPropMenu
     {
 #if VRM_DEVELOP
-        [MenuItem("VRMShaders/PreExport ShaderProps")]
+        [MenuItem("VRMShaders/Development/PreExport ShaderProps")]
 #endif
         public static void PreExport()
         {