diff --git a/Assets/UniGLTF/Editor/Generator/DeserializerWriter.cs b/Assets/UniGLTF/Editor/Generator/DeserializerWriter.cs
index d5ce549cb..eaae7f986 100644
--- a/Assets/UniGLTF/Editor/Generator/DeserializerWriter.cs
+++ b/Assets/UniGLTF/Editor/Generator/DeserializerWriter.cs
@@ -16,6 +16,7 @@ namespace UniGLTF.Extensions.$0 {
 
 public static class GltfDeserializer
 {
+    public static readonly Utf8String ExtensionNameUtf8 = Utf8String.From($0.ExtensionName);
 
 public static bool TryGet(UniGLTF.glTFExtension src, out $0 extension)
 {
@@ -23,7 +24,7 @@ public static bool TryGet(UniGLTF.glTFExtension src, out $0 extension)
     {
         foreach(var kv in extensions.ObjectItems())
         {
-            if(kv.Key.GetUtf8String() == $0.ExtensionNameUtf8)
+            if(kv.Key.GetUtf8String() == ExtensionNameUtf8)
             {
                 extension = Deserialize(kv.Value);
                 return true;
diff --git a/Assets/UniGLTF/Editor/Generator/FormatWriter.cs b/Assets/UniGLTF/Editor/Generator/FormatWriter.cs
index d102bd91f..9fb9be3e9 100644
--- a/Assets/UniGLTF/Editor/Generator/FormatWriter.cs
+++ b/Assets/UniGLTF/Editor/Generator/FormatWriter.cs
@@ -19,29 +19,6 @@ namespace GenerateUniGLTFSerialization
             m_prefix = prefix;
         }
 
-        // static string UpperCamelCase(string src)
-        // {
-        //     if(string.IsNullOrEmpty(src))
-        //     {
-        //         return "";
-        //     }
-        //     return src.Substring(0, 1).ToUpper() + src.Substring(1);
-        // }
-
-        // string ClassName(string src)
-        // {
-        //     if(string.IsNullOrEmpty(src))
-        //     {
-        //         // root
-        //         return m_prefix;
-        //     }
-        //     else{
-        //         return String.Join("", src.Split("__").Select(x => UpperCamelCase(x)));
-        //     }
-        // }
-
-        const string EnumStringAttr = "[JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]";
-
         static (string, string) PropType(JsonSchemaBase schema)
         {
             switch (schema.JsonSchemaType)
@@ -55,7 +32,7 @@ namespace GenerateUniGLTFSerialization
                     return (null, schema.ValueType);
 
                 case JsonSchemaType.EnumString:
-                    return (EnumStringAttr, schema.ValueType);
+                    return (null, schema.ValueType);
             }
 
             throw new NotImplementedException();
@@ -81,7 +58,6 @@ namespace GenerateUniGLTFSerialization
             {
                 var indent = "        ";
                 m_w.WriteLine($"{indent}public const string ExtensionName = \"{rootName}\";");
-                m_w.WriteLine($"{indent}public static readonly Utf8String ExtensionNameUtf8 = Utf8String.From(ExtensionName);");
                 m_w.WriteLine();
             }
 
@@ -178,8 +154,7 @@ namespace GenerateUniGLTFSerialization
             w.Write($@"// This file is generated from JsonSchema. Don't modify this source code.
 using System;
 using System.Collections.Generic;
-using UniGLTF;
-using UniJSON;
+
 
 namespace UniGLTF.Extensions.{rootName}
 {{
diff --git a/Assets/UniGLTF/Editor/JsonSchema/Schemas/ExtensionJsonSchema.cs b/Assets/UniGLTF/Editor/JsonSchema/Schemas/ExtensionJsonSchema.cs
index 11cd401e1..7a83dfdf9 100644
--- a/Assets/UniGLTF/Editor/JsonSchema/Schemas/ExtensionJsonSchema.cs
+++ b/Assets/UniGLTF/Editor/JsonSchema/Schemas/ExtensionJsonSchema.cs
@@ -9,7 +9,7 @@ namespace UniGLTF.JsonSchema.Schemas
         {
         }
 
-        public override string ValueType => "glTFExtension";
+        public override string ValueType => "object";
 
         public override bool IsInline => true;
 
@@ -25,7 +25,7 @@ namespace UniGLTF.JsonSchema.Schemas
 
         public override string GenerateSerializerCall(string callName, string argName)
         {
-            return $"{argName}.Serialize(f)";
+            return $"({argName} as glTFExtension).Serialize(f)";
         }
     }
 }
diff --git a/Assets/VRM10/Editor/GeneratorMenu.cs b/Assets/VRM10/Editor/GeneratorMenu.cs
index ba76317d3..c2e084fb0 100644
--- a/Assets/VRM10/Editor/GeneratorMenu.cs
+++ b/Assets/VRM10/Editor/GeneratorMenu.cs
@@ -7,18 +7,15 @@ namespace UniVRM10
     /// <summary>
     /// JsonSchema から vrm10 のシリアライザーを生成する。
     /// 
-    /// * https://github.com/KhronosGroup/glTF
-    /// * https://github.com/vrm-c/vrm-specification
-    /// 
-    /// を UniVRM の隣に clone しておくこと。
-    /// 
-    /// * UniVRM
     /// * glTF
     /// * vrm-specification
     /// 
+    /// は SubModuleになった。 `$ git submodule update --init` しておくこと。
+    /// 
     /// </summary>
     public static class Menu
     {
+#if VRM_DEVELOP        
         [MenuItem(UniVRM10.VRMVersion.MENU + "/Generate from JsonSchema")]
         public static void Generate()
         {
@@ -30,6 +27,7 @@ namespace UniVRM10
         {
             Run(true);
         }
+#endif
 
         static void Run(bool debug)
         {
diff --git a/Assets/VRM10/Runtime/Format/Constraints/Deserializer.g.cs b/Assets/VRM10/Runtime/Format/Constraints/Deserializer.g.cs
index ce4d738a7..04fa4b622 100644
--- a/Assets/VRM10/Runtime/Format/Constraints/Deserializer.g.cs
+++ b/Assets/VRM10/Runtime/Format/Constraints/Deserializer.g.cs
@@ -8,6 +8,7 @@ namespace UniGLTF.Extensions.VRMC_node_constraint {
 
 public static class GltfDeserializer
 {
+    public static readonly Utf8String ExtensionNameUtf8 = Utf8String.From(VRMC_node_constraint.ExtensionName);
 
 public static bool TryGet(UniGLTF.glTFExtension src, out VRMC_node_constraint extension)
 {
@@ -15,7 +16,7 @@ public static bool TryGet(UniGLTF.glTFExtension src, out VRMC_node_constraint ex
     {
         foreach(var kv in extensions.ObjectItems())
         {
-            if(kv.Key.GetUtf8String() == VRMC_node_constraint.ExtensionNameUtf8)
+            if(kv.Key.GetUtf8String() == ExtensionNameUtf8)
             {
                 extension = Deserialize(kv.Value);
                 return true;
diff --git a/Assets/VRM10/Runtime/Format/Constraints/Format.g.cs b/Assets/VRM10/Runtime/Format/Constraints/Format.g.cs
index 13a812f1c..0d3af20a9 100644
--- a/Assets/VRM10/Runtime/Format/Constraints/Format.g.cs
+++ b/Assets/VRM10/Runtime/Format/Constraints/Format.g.cs
@@ -1,8 +1,7 @@
 // This file is generated from JsonSchema. Don't modify this source code.
 using System;
 using System.Collections.Generic;
-using UniGLTF;
-using UniJSON;
+
 
 namespace UniGLTF.Extensions.VRMC_node_constraint
 {
@@ -17,10 +16,10 @@ namespace UniGLTF.Extensions.VRMC_node_constraint
     public class PositionConstraint
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // The user-defined name of this object.
         public string Name;
@@ -29,11 +28,9 @@ namespace UniGLTF.Extensions.VRMC_node_constraint
         public int? Source;
 
         // The source node will be evaluated in this space.
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ObjectSpace SourceSpace;
 
         // The destination node will be evaluated in this space.
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ObjectSpace DestinationSpace;
 
         // Axes be constrained by this constraint, in X-Y-Z order.
@@ -46,10 +43,10 @@ namespace UniGLTF.Extensions.VRMC_node_constraint
     public class RotationConstraint
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // The user-defined name of this object.
         public string Name;
@@ -58,11 +55,9 @@ namespace UniGLTF.Extensions.VRMC_node_constraint
         public int? Source;
 
         // The source node will be evaluated in this space.
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ObjectSpace SourceSpace;
 
         // The destination node will be evaluated in this space.
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ObjectSpace DestinationSpace;
 
         // Axes be constrained by this constraint, in X-Y-Z order.
@@ -75,10 +70,10 @@ namespace UniGLTF.Extensions.VRMC_node_constraint
     public class AimConstraint
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // The user-defined name of this object.
         public string Name;
@@ -87,11 +82,9 @@ namespace UniGLTF.Extensions.VRMC_node_constraint
         public int? Source;
 
         // The source node will be evaluated in this space.
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ObjectSpace SourceSpace;
 
         // The destination node will be evaluated in this space.
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ObjectSpace DestinationSpace;
 
         // An axis which faces the direction of its source.
@@ -110,10 +103,10 @@ namespace UniGLTF.Extensions.VRMC_node_constraint
     public class Constraint
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // A constraint that links the position with a source.
         public PositionConstraint Position;
@@ -128,13 +121,12 @@ namespace UniGLTF.Extensions.VRMC_node_constraint
     public class VRMC_node_constraint
     {
         public const string ExtensionName = "VRMC_node_constraint";
-        public static readonly Utf8String ExtensionNameUtf8 = Utf8String.From(ExtensionName);
 
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // Contains position, rotation, or aim
         public Constraint Constraint;
diff --git a/Assets/VRM10/Runtime/Format/Constraints/Serializer.g.cs b/Assets/VRM10/Runtime/Format/Constraints/Serializer.g.cs
index 35356e461..02b319f02 100644
--- a/Assets/VRM10/Runtime/Format/Constraints/Serializer.g.cs
+++ b/Assets/VRM10/Runtime/Format/Constraints/Serializer.g.cs
@@ -35,12 +35,12 @@ public static void Serialize(JsonFormatter f, VRMC_node_constraint value)
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Constraint!=null){
@@ -58,12 +58,12 @@ public static void Serialize_Constraint(JsonFormatter f, Constraint value)
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Position!=null){
@@ -91,12 +91,12 @@ public static void __constraint_Serialize_Position(JsonFormatter f, PositionCons
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(!string.IsNullOrEmpty(value.Name)){
@@ -151,12 +151,12 @@ public static void __constraint_Serialize_Rotation(JsonFormatter f, RotationCons
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(!string.IsNullOrEmpty(value.Name)){
@@ -211,12 +211,12 @@ public static void __constraint_Serialize_Aim(JsonFormatter f, AimConstraint val
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(!string.IsNullOrEmpty(value.Name)){
diff --git a/Assets/VRM10/Runtime/Format/MaterialsMToon/Deserializer.g.cs b/Assets/VRM10/Runtime/Format/MaterialsMToon/Deserializer.g.cs
index 3d6714e44..12cedff0c 100644
--- a/Assets/VRM10/Runtime/Format/MaterialsMToon/Deserializer.g.cs
+++ b/Assets/VRM10/Runtime/Format/MaterialsMToon/Deserializer.g.cs
@@ -8,6 +8,7 @@ namespace UniGLTF.Extensions.VRMC_materials_mtoon {
 
 public static class GltfDeserializer
 {
+    public static readonly Utf8String ExtensionNameUtf8 = Utf8String.From(VRMC_materials_mtoon.ExtensionName);
 
 public static bool TryGet(UniGLTF.glTFExtension src, out VRMC_materials_mtoon extension)
 {
@@ -15,7 +16,7 @@ public static bool TryGet(UniGLTF.glTFExtension src, out VRMC_materials_mtoon ex
     {
         foreach(var kv in extensions.ObjectItems())
         {
-            if(kv.Key.GetUtf8String() == VRMC_materials_mtoon.ExtensionNameUtf8)
+            if(kv.Key.GetUtf8String() == ExtensionNameUtf8)
             {
                 extension = Deserialize(kv.Value);
                 return true;
diff --git a/Assets/VRM10/Runtime/Format/MaterialsMToon/Format.g.cs b/Assets/VRM10/Runtime/Format/MaterialsMToon/Format.g.cs
index 1812ab9cb..91a660a4d 100644
--- a/Assets/VRM10/Runtime/Format/MaterialsMToon/Format.g.cs
+++ b/Assets/VRM10/Runtime/Format/MaterialsMToon/Format.g.cs
@@ -1,8 +1,7 @@
 // This file is generated from JsonSchema. Don't modify this source code.
 using System;
 using System.Collections.Generic;
-using UniGLTF;
-using UniJSON;
+
 
 namespace UniGLTF.Extensions.VRMC_materials_mtoon
 {
@@ -10,10 +9,10 @@ namespace UniGLTF.Extensions.VRMC_materials_mtoon
     public class TextureInfo
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // The index of the texture.
         public int? Index;
@@ -25,10 +24,10 @@ namespace UniGLTF.Extensions.VRMC_materials_mtoon
     public class ShadingShiftTextureInfo
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // The index of the texture.
         public int? Index;
@@ -51,13 +50,12 @@ namespace UniGLTF.Extensions.VRMC_materials_mtoon
     public class VRMC_materials_mtoon
     {
         public const string ExtensionName = "VRMC_materials_mtoon";
-        public static readonly Utf8String ExtensionNameUtf8 = Utf8String.From(ExtensionName);
 
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // Meta
         public string Version;
@@ -96,7 +94,6 @@ namespace UniGLTF.Extensions.VRMC_materials_mtoon
         public float? ParametricRimLiftFactor;
 
         // Outline
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public OutlineWidthMode OutlineWidthMode;
 
         public float? OutlineWidthFactor;
diff --git a/Assets/VRM10/Runtime/Format/MaterialsMToon/Serializer.g.cs b/Assets/VRM10/Runtime/Format/MaterialsMToon/Serializer.g.cs
index b6e3369a2..397041fca 100644
--- a/Assets/VRM10/Runtime/Format/MaterialsMToon/Serializer.g.cs
+++ b/Assets/VRM10/Runtime/Format/MaterialsMToon/Serializer.g.cs
@@ -35,12 +35,12 @@ public static void Serialize(JsonFormatter f, VRMC_materials_mtoon value)
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(!string.IsNullOrEmpty(value.Version)){
@@ -185,12 +185,12 @@ public static void Serialize_ShadeMultiplyTexture(JsonFormatter f, TextureInfo v
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Index.HasValue){
@@ -213,12 +213,12 @@ public static void Serialize_ShadingShiftTexture(JsonFormatter f, ShadingShiftTe
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Index.HasValue){
@@ -246,12 +246,12 @@ public static void Serialize_MatcapTexture(JsonFormatter f, TextureInfo value)
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Index.HasValue){
@@ -286,12 +286,12 @@ public static void Serialize_RimMultiplyTexture(JsonFormatter f, TextureInfo val
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Index.HasValue){
@@ -314,12 +314,12 @@ public static void Serialize_OutlineWidthMultiplyTexture(JsonFormatter f, Textur
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Index.HasValue){
@@ -354,12 +354,12 @@ public static void Serialize_UvAnimationMaskTexture(JsonFormatter f, TextureInfo
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Index.HasValue){
diff --git a/Assets/VRM10/Runtime/Format/SpringBone/Deserializer.g.cs b/Assets/VRM10/Runtime/Format/SpringBone/Deserializer.g.cs
index 1d6b3a46c..28fe96538 100644
--- a/Assets/VRM10/Runtime/Format/SpringBone/Deserializer.g.cs
+++ b/Assets/VRM10/Runtime/Format/SpringBone/Deserializer.g.cs
@@ -8,6 +8,7 @@ namespace UniGLTF.Extensions.VRMC_springBone {
 
 public static class GltfDeserializer
 {
+    public static readonly Utf8String ExtensionNameUtf8 = Utf8String.From(VRMC_springBone.ExtensionName);
 
 public static bool TryGet(UniGLTF.glTFExtension src, out VRMC_springBone extension)
 {
@@ -15,7 +16,7 @@ public static bool TryGet(UniGLTF.glTFExtension src, out VRMC_springBone extensi
     {
         foreach(var kv in extensions.ObjectItems())
         {
-            if(kv.Key.GetUtf8String() == VRMC_springBone.ExtensionNameUtf8)
+            if(kv.Key.GetUtf8String() == ExtensionNameUtf8)
             {
                 extension = Deserialize(kv.Value);
                 return true;
diff --git a/Assets/VRM10/Runtime/Format/SpringBone/Format.g.cs b/Assets/VRM10/Runtime/Format/SpringBone/Format.g.cs
index b4124a382..122860d74 100644
--- a/Assets/VRM10/Runtime/Format/SpringBone/Format.g.cs
+++ b/Assets/VRM10/Runtime/Format/SpringBone/Format.g.cs
@@ -1,8 +1,7 @@
 // This file is generated from JsonSchema. Don't modify this source code.
 using System;
 using System.Collections.Generic;
-using UniGLTF;
-using UniJSON;
+
 
 namespace UniGLTF.Extensions.VRMC_springBone
 {
@@ -31,10 +30,10 @@ namespace UniGLTF.Extensions.VRMC_springBone
     public class ColliderShape
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         public ColliderShapeSphere Sphere;
 
@@ -44,10 +43,10 @@ namespace UniGLTF.Extensions.VRMC_springBone
     public class Collider
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // The node index.
         public int? Node;
@@ -58,10 +57,10 @@ namespace UniGLTF.Extensions.VRMC_springBone
     public class ColliderGroup
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         public List<Collider> Colliders;
     }
@@ -69,10 +68,10 @@ namespace UniGLTF.Extensions.VRMC_springBone
     public class SpringBoneJoint
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // The node index.
         public int? Node;
@@ -96,10 +95,10 @@ namespace UniGLTF.Extensions.VRMC_springBone
     public class Spring
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // Name of the Spring
         public string Name;
@@ -114,13 +113,12 @@ namespace UniGLTF.Extensions.VRMC_springBone
     public class VRMC_springBone
     {
         public const string ExtensionName = "VRMC_springBone";
-        public static readonly Utf8String ExtensionNameUtf8 = Utf8String.From(ExtensionName);
 
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // An array of colliderGroups.
         public List<ColliderGroup> ColliderGroups;
diff --git a/Assets/VRM10/Runtime/Format/SpringBone/Serializer.g.cs b/Assets/VRM10/Runtime/Format/SpringBone/Serializer.g.cs
index 38e423999..ef63c1cd2 100644
--- a/Assets/VRM10/Runtime/Format/SpringBone/Serializer.g.cs
+++ b/Assets/VRM10/Runtime/Format/SpringBone/Serializer.g.cs
@@ -35,12 +35,12 @@ public static void Serialize(JsonFormatter f, VRMC_springBone value)
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.ColliderGroups!=null&&value.ColliderGroups.Count()>=0){
@@ -75,12 +75,12 @@ public static void Serialize_ColliderGroups_ITEM(JsonFormatter f, ColliderGroup
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Colliders!=null&&value.Colliders.Count()>=0){
@@ -110,12 +110,12 @@ public static void __colliderGroups_ITEM_Serialize_Colliders_ITEM(JsonFormatter
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Node.HasValue){
@@ -138,12 +138,12 @@ public static void __colliderGroups_ITEM__colliders_ITEM_Serialize_Shape(JsonFor
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Sphere!=null){
@@ -255,12 +255,12 @@ public static void Serialize_Springs_ITEM(JsonFormatter f, Spring value)
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(!string.IsNullOrEmpty(value.Name)){
@@ -300,12 +300,12 @@ public static void __springs_ITEM_Serialize_Joints_ITEM(JsonFormatter f, SpringB
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Node.HasValue){
diff --git a/Assets/VRM10/Runtime/Format/Vrm/Deserializer.g.cs b/Assets/VRM10/Runtime/Format/Vrm/Deserializer.g.cs
index fef0de1f1..20a866f87 100644
--- a/Assets/VRM10/Runtime/Format/Vrm/Deserializer.g.cs
+++ b/Assets/VRM10/Runtime/Format/Vrm/Deserializer.g.cs
@@ -8,6 +8,7 @@ namespace UniGLTF.Extensions.VRMC_vrm {
 
 public static class GltfDeserializer
 {
+    public static readonly Utf8String ExtensionNameUtf8 = Utf8String.From(VRMC_vrm.ExtensionName);
 
 public static bool TryGet(UniGLTF.glTFExtension src, out VRMC_vrm extension)
 {
@@ -15,7 +16,7 @@ public static bool TryGet(UniGLTF.glTFExtension src, out VRMC_vrm extension)
     {
         foreach(var kv in extensions.ObjectItems())
         {
-            if(kv.Key.GetUtf8String() == VRMC_vrm.ExtensionNameUtf8)
+            if(kv.Key.GetUtf8String() == ExtensionNameUtf8)
             {
                 extension = Deserialize(kv.Value);
                 return true;
diff --git a/Assets/VRM10/Runtime/Format/Vrm/Format.g.cs b/Assets/VRM10/Runtime/Format/Vrm/Format.g.cs
index 60319c844..22167bc20 100644
--- a/Assets/VRM10/Runtime/Format/Vrm/Format.g.cs
+++ b/Assets/VRM10/Runtime/Format/Vrm/Format.g.cs
@@ -1,8 +1,7 @@
 // This file is generated from JsonSchema. Don't modify this source code.
 using System;
 using System.Collections.Generic;
-using UniGLTF;
-using UniJSON;
+
 
 namespace UniGLTF.Extensions.VRMC_vrm
 {
@@ -66,7 +65,6 @@ namespace UniGLTF.Extensions.VRMC_vrm
         public int? ThumbnailImage;
 
         // A person who can perform with this avatars
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public AvatarPermissionType AvatarPermission;
 
         // A flag that permits to use this avatar in excessively violent contents
@@ -76,21 +74,18 @@ namespace UniGLTF.Extensions.VRMC_vrm
         public bool? AllowExcessivelySexualUsage;
 
         // An option that permits to use this avatar in commercial products
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public CommercialUsageType CommercialUsage;
 
         // A flag that permits to use this avatar in political or religious contents
         public bool? AllowPoliticalOrReligiousUsage;
 
         // An option that forces or abandons to display the credit of this avatar
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public CreditNotationType CreditNotation;
 
         // A flag that permits to redistribute this avatar
         public bool? AllowRedistribution;
 
         // An option that controls the condition to modify this avatar
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ModificationType Modification;
 
         // Describe the URL links of other license
@@ -292,7 +287,6 @@ namespace UniGLTF.Extensions.VRMC_vrm
         public int? Node;
 
         // How the camera interprets the mesh.
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public FirstPersonType Type;
     }
 
@@ -323,7 +317,6 @@ namespace UniGLTF.Extensions.VRMC_vrm
         // The origin of LookAt. Position offset from the head bone
         public float[] OffsetFromHeadBone;
 
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public LookAtType Type;
 
         // Horizontal inward movement. The left eye moves right. The right eye moves left.
@@ -366,10 +359,10 @@ namespace UniGLTF.Extensions.VRMC_vrm
     public class MorphTargetBind
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // The index of the node that attached to target mesh.
         public int? Node;
@@ -394,15 +387,14 @@ namespace UniGLTF.Extensions.VRMC_vrm
     public class MaterialColorBind
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // target material
         public int? Material;
 
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public MaterialColorType Type;
 
         // target color
@@ -412,10 +404,10 @@ namespace UniGLTF.Extensions.VRMC_vrm
     public class TextureTransformBind
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // target material
         public int? Material;
@@ -438,16 +430,15 @@ namespace UniGLTF.Extensions.VRMC_vrm
     public class Expression
     {
         // Dictionary object with extension-specific objects.
-        public glTFExtension Extensions;
+        public object Extensions;
 
         // Application-specific data.
-        public glTFExtension Extras;
+        public object Extras;
 
         // Use only if the preset is custom. Unique within the model
         public string Name;
 
         // Functions of Expression
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ExpressionPreset Preset;
 
         // Specify a morph target
@@ -463,22 +454,18 @@ namespace UniGLTF.Extensions.VRMC_vrm
         public bool? IsBinary;
 
         // Override values of Blink expressions when this Expression is enabled
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ExpressionOverrideType OverrideBlink;
 
         // Override values of LookAt expressions when this Expression is enabled
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ExpressionOverrideType OverrideLookAt;
 
         // Override values of Mouth expressions when this Expression is enabled
-        [JsonSchema(EnumSerializationType = EnumSerializationType.AsString)]
         public ExpressionOverrideType OverrideMouth;
     }
 
     public class VRMC_vrm
     {
         public const string ExtensionName = "VRMC_vrm";
-        public static readonly Utf8String ExtensionNameUtf8 = Utf8String.From(ExtensionName);
 
         // Specification version of the VRM
         public string SpecVersion;
diff --git a/Assets/VRM10/Runtime/Format/Vrm/Serializer.g.cs b/Assets/VRM10/Runtime/Format/Vrm/Serializer.g.cs
index c5dc200a8..610fec3c9 100644
--- a/Assets/VRM10/Runtime/Format/Vrm/Serializer.g.cs
+++ b/Assets/VRM10/Runtime/Format/Vrm/Serializer.g.cs
@@ -1378,12 +1378,12 @@ public static void Serialize_Expressions_ITEM(JsonFormatter f, Expression value)
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(!string.IsNullOrEmpty(value.Name)){
@@ -1453,12 +1453,12 @@ public static void __expressions_ITEM_Serialize_MorphTargetBinds_ITEM(JsonFormat
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Node.HasValue){
@@ -1498,12 +1498,12 @@ public static void __expressions_ITEM_Serialize_MaterialColorBinds_ITEM(JsonForm
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Material.HasValue){
@@ -1555,12 +1555,12 @@ public static void __expressions_ITEM_Serialize_TextureTransformBinds_ITEM(JsonF
 
     if(value.Extensions!=null){
         f.Key("extensions");                
-        value.Extensions.Serialize(f);
+        (value.Extensions as glTFExtension).Serialize(f);
     }
 
     if(value.Extras!=null){
         f.Key("extras");                
-        value.Extras.Serialize(f);
+        (value.Extras as glTFExtension).Serialize(f);
     }
 
     if(value.Material.HasValue){
diff --git a/Assets/VRM10/Tests/MigrationTests.cs b/Assets/VRM10/Tests/MigrationTests.cs
index e60a69d51..5329888b6 100644
--- a/Assets/VRM10/Tests/MigrationTests.cs
+++ b/Assets/VRM10/Tests/MigrationTests.cs
@@ -54,9 +54,9 @@ namespace UniVRM10
             var json = glb.Json.Bytes.ParseAsJson();
             var gltf = UniGLTF.GltfDeserializer.Deserialize(json);
 
-            MigrationVrm.Check(vrm0Json, GetExtension(gltf.extensions, UniGLTF.Extensions.VRMC_vrm.VRMC_vrm.ExtensionNameUtf8,
+            MigrationVrm.Check(vrm0Json, GetExtension(gltf.extensions, UniGLTF.Extensions.VRMC_vrm.GltfDeserializer.ExtensionNameUtf8,
                 UniGLTF.Extensions.VRMC_vrm.GltfDeserializer.Deserialize));
-            MigrationVrm.Check(vrm0Json, GetExtension(gltf.extensions, UniGLTF.Extensions.VRMC_springBone.VRMC_springBone.ExtensionNameUtf8,
+            MigrationVrm.Check(vrm0Json, GetExtension(gltf.extensions, UniGLTF.Extensions.VRMC_springBone.GltfDeserializer.ExtensionNameUtf8,
                 UniGLTF.Extensions.VRMC_springBone.GltfDeserializer.Deserialize), gltf.nodes);
         }