diff --git a/Assets/VRM/UniGLTF/Editor/Tests/MaterialTests.cs b/Assets/VRM/UniGLTF/Editor/Tests/MaterialTests.cs
index ca66cd670..b2575fbdd 100644
--- a/Assets/VRM/UniGLTF/Editor/Tests/MaterialTests.cs
+++ b/Assets/VRM/UniGLTF/Editor/Tests/MaterialTests.cs
@@ -29,6 +29,7 @@ namespace UniGLTF
 
             var materialExporter = new MaterialExporter();
             var gltfMaterial = materialExporter.ExportMaterial(srcMaterial, textureManager);
+            gltfMaterial.pbrMetallicRoughness.baseColorTexture.extensions.Parse();
 
             var shaderStore = new ShaderStore(null);
             var materialImporter = new MaterialImporter(shaderStore, (int index) => { return null; });
diff --git a/Assets/VRM/UniGLTF/Scripts/Format/ExtensionsAndExtras/gltfExtension.cs b/Assets/VRM/UniGLTF/Scripts/Format/ExtensionsAndExtras/gltfExtension.cs
index 6efc2b539..075de1ce1 100644
--- a/Assets/VRM/UniGLTF/Scripts/Format/ExtensionsAndExtras/gltfExtension.cs
+++ b/Assets/VRM/UniGLTF/Scripts/Format/ExtensionsAndExtras/gltfExtension.cs
@@ -28,7 +28,7 @@ namespace UniGLTF
         #endregion
 
         #region for Import
-        readonly ListTreeNode<JsonValue> m_json;
+        ListTreeNode<JsonValue> m_json;
         public glTFExtension(ListTreeNode<JsonValue> json)
         {
             m_json = json;
@@ -45,6 +45,27 @@ namespace UniGLTF
             }
         }
         #endregion
+
+        /// <summary>
+        /// for unit test
+        /// 
+        /// parse exported value
+        /// </summary>
+        public void Parse()
+        {
+            var f = new JsonFormatter();
+            f.BeginMap();
+            foreach (var kv in Serialized)
+            {
+                f.Key(kv.Key);
+                f.Raw(kv.Value);
+            }
+            f.EndMap();
+
+            var b = f.GetStoreBytes();
+            var json = Encoding.UTF8.GetString(b.Array, b.Offset, b.Count);
+            m_json = json.ParseAsJson();
+        }
     }
 
     public static class GltfExtensionFormatterExtensions
diff --git a/Assets/VRM/UniGLTF/Scripts/Format/ExtensionsAndExtras/gltf_mesh_extras_targetNames.cs b/Assets/VRM/UniGLTF/Scripts/Format/ExtensionsAndExtras/gltf_mesh_extras_targetNames.cs
index ccc02c4c4..5e7d172af 100644
--- a/Assets/VRM/UniGLTF/Scripts/Format/ExtensionsAndExtras/gltf_mesh_extras_targetNames.cs
+++ b/Assets/VRM/UniGLTF/Scripts/Format/ExtensionsAndExtras/gltf_mesh_extras_targetNames.cs
@@ -33,17 +33,20 @@ namespace UniGLTF
 
         public static bool TryGet(glTFMesh mesh, out List<string> targetNames)
         {
-            foreach (var kv in mesh.extras.ObjectItems())
+            if (mesh.extras != null)
             {
-                if (kv.Key.GetUtf8String() == ExtraNameUtf8)
+                foreach (var kv in mesh.extras.ObjectItems())
                 {
-                    targetNames = Deserialize(kv.Value);
-                    return true;
+                    if (kv.Key.GetUtf8String() == ExtraNameUtf8)
+                    {
+                        targetNames = Deserialize(kv.Value);
+                        return true;
+                    }
                 }
             }
 
             // use first primitive
-            if (mesh.primitives.Count > 0)
+            if (mesh.primitives.Count > 0 && mesh.primitives[0].extras != null)
             {
                 foreach (var kv in mesh.primitives[0].extras.ObjectItems())
                 {
diff --git a/Assets/VRM/UniGLTF/Scripts/IO/AnimationImporter.cs b/Assets/VRM/UniGLTF/Scripts/IO/AnimationImporter.cs
index 50c46f172..85e2e9e08 100644
--- a/Assets/VRM/UniGLTF/Scripts/IO/AnimationImporter.cs
+++ b/Assets/VRM/UniGLTF/Scripts/IO/AnimationImporter.cs
@@ -268,20 +268,10 @@ namespace UniGLTF
                                 var primitive = mesh.primitives.FirstOrDefault();
                                 var targets = primitive.targets;
 
-                                List<string> targetNames;
-                                throw new NotImplementedException();
-                                // if(primitive != null && primitive.extras != null && primitive.extras.targetNames != null && primitive.extras.targetNames.Count > 0)
-                                // {
-                                //     targetNames = primitive.extras.targetNames;
-                                // }
-                                // else if(mesh.extras != null && mesh.extras.targetNames != null && mesh.extras.targetNames.Count > 0)
-                                // {
-                                //     targetNames = mesh.extras.targetNames;
-                                // }
-                                // else
-                                // {
-                                //     throw new Exception("glTF BlendShape Animation. targetNames invalid.");
-                                // }
+                                if (!gltf_mesh_extras_targetNames.TryGet(mesh, out List<string> targetNames))
+                                {
+                                    throw new Exception("glTF BlendShape Animation. targetNames invalid.");
+                                }
 
                                 var keyNames = targetNames
                                     .Where(x => !string.IsNullOrEmpty(x))
@@ -307,7 +297,7 @@ namespace UniGLTF
                                         }
                                         return values;
                                     });
-                                
+
                             }
                             break;
 
diff --git a/Assets/VRM/UniVRM/Editor/Tests/UniVRMSerializeTests.cs b/Assets/VRM/UniVRM/Editor/Tests/UniVRMSerializeTests.cs
index 67c586268..6e1ca4aab 100644
--- a/Assets/VRM/UniVRM/Editor/Tests/UniVRMSerializeTests.cs
+++ b/Assets/VRM/UniVRM/Editor/Tests/UniVRMSerializeTests.cs
@@ -59,35 +59,91 @@ namespace VRM
         }
 
         public static string ToJson(this glTF_VRM_MaterialValueBind self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_BlendShapeBind self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_BlendShapeGroup self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_DegreeMap self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_MeshAnnotation self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_Firstperson self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_HumanoidBone self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_Humanoid self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_Material self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_Meta self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_SecondaryAnimationCollider self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
         public static string ToJson(this glTF_VRM_SecondaryAnimationColliderGroup self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
 
         public static string ToJson(this glTF_VRM_SecondaryAnimationGroup self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
 
         public static string ToJson(this glTF_VRM_SecondaryAnimation self)
-        { return ""; }
+        {
+            var f = new JsonFormatter();
+            f.GenSerialize(self);
+            return f.ToString();
+        }
     }
 
     public class UniVRMSerializeTests