diff --git a/Assets/VRM_Samples/BlendShapeMenu.meta b/Assets/VRM_Samples/BlendShapeMenu.meta
new file mode 100644
index 000000000..13cbe9d10
--- /dev/null
+++ b/Assets/VRM_Samples/BlendShapeMenu.meta
@@ -0,0 +1,8 @@
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diff --git a/Assets/VRM_Samples/BlendShapeMenu/AddBlankForPerfectSync.cs b/Assets/VRM_Samples/BlendShapeMenu/AddBlankForPerfectSync.cs
new file mode 100644
index 000000000..306057ea6
--- /dev/null
+++ b/Assets/VRM_Samples/BlendShapeMenu/AddBlankForPerfectSync.cs
@@ -0,0 +1,120 @@
+using System.Text;
+using UnityEditor;
+using UnityEngine;
+
+namespace VRM.Sample.BlendShapeMenu
+{
+    public static class BlendShapeMenu
+    {
+        static string[] NAMES = new string[]
+        {
+            "BrowInnerUp",
+            "BrowDownLeft",
+            "BrowDownRight",
+            "BrowOuterUpLeft",
+            "BrowOuterUpRight",
+            "EyeLookUpLeft",
+            "EyeLookUpRight",
+            "EyeLookDownLeft",
+            "EyeLookDownRight",
+            "EyeLookInLeft",
+            "EyeLookInRight",
+            "EyeLookOutLeft",
+            "EyeLookOutRight",
+            "EyeBlinkLeft",
+            "EyeBlinkRight",
+            "EyeSquintRight",
+            "EyeSquintLeft",
+            "EyeWideLeft",
+            "EyeWideRight",
+            "CheekPuff",
+            "CheekSquintLeft",
+            "CheekSquintRight",
+            "NoseSneerLeft",
+            "NoseSneerRight",
+            "JawOpen",
+            "JawForward",
+            "JawLeft",
+            "JawRight",
+            "MouthFunnel",
+            "MouthPucker",
+            "MouthLeft",
+            "MouthRight",
+            "MouthRollUpper",
+            "MouthRollLower",
+            "MouthShrugUpper",
+            "MouthShrugLower",
+            "MouthClose",
+            "MouthSmileLeft",
+            "MouthSmileRight",
+            "MouthFrownLeft",
+            "MouthFrownRight",
+            "MouthDimpleLeft",
+            "MouthDimpleRight",
+            "MouthUpperUpLeft",
+            "MouthUpperUpRight",
+            "MouthLowerDownLeft",
+            "MouthLowerDownRight",
+            "MouthPressLeft",
+            "MouthPressRight",
+            "MouthStretchLeft",
+            "MouthStretchRight",
+            "TongueOut",
+        };
+
+        [MenuItem("CONTEXT/BlendShapeAvatar/AddBlankForPerfectSync")]
+        public static void AddBlankForPerfectSync(MenuCommand command)
+        {
+            // Debug.Log(command.context);
+            var avatar = command.context as BlendShapeAvatar;
+            if (avatar == null)
+            {
+                Debug.LogError("no context");
+                return;
+            }
+
+            var assetPath = AssetDatabase.GetAssetPath(avatar);
+
+            var dir = EditorUtility.SaveFolderPanel("blendshape folder", assetPath, "");
+            if (string.IsNullOrEmpty(dir))
+            {
+                // cancel
+                return;
+            }
+
+            if (!dir.StartsWith(Application.dataPath))
+            {
+                // not in Assets
+                EditorUtility.DisplayDialog("error", "folder is not in Assets", "ok");
+                return;
+            }
+
+            var assetDir = "Assets" + dir.Substring(Application.dataPath.Length);
+            var sb = new StringBuilder();
+            foreach (var name in NAMES)
+            {
+                if (avatar.Clips.Find(x => x.Preset == BlendShapePreset.Unknown && x.BlendShapeName == name))
+                {
+                    // already exists
+                    continue;
+                }
+
+                // new blendshape clip
+                var clip = ScriptableObject.CreateInstance<BlendShapeClip>();
+                clip.Preset = BlendShapePreset.Unknown;
+                clip.name = name;
+                clip.BlendShapeName = name;
+
+                // write blendshape clip
+                var clipPath = $"{assetDir}/{name}.asset";
+                sb.AppendLine($"{clipPath}");
+                AssetDatabase.CreateAsset(clip, clipPath);
+
+                // add to avatar
+                avatar.Clips.Add(clip);
+            }
+
+            Debug.Log(sb.ToString());
+        }
+    }
+}
diff --git a/Assets/VRM_Samples/BlendShapeMenu/AddBlankForPerfectSync.cs.meta b/Assets/VRM_Samples/BlendShapeMenu/AddBlankForPerfectSync.cs.meta
new file mode 100644
index 000000000..2a257caea
--- /dev/null
+++ b/Assets/VRM_Samples/BlendShapeMenu/AddBlankForPerfectSync.cs.meta
@@ -0,0 +1,11 @@
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