diff --git a/Assets/VRM/UniVRM/Editor/Tests/VRMBlendShapeKeyTest.cs b/Assets/VRM/UniVRM/Editor/Tests/VRMBlendShapeKeyTest.cs
index e24e2c215..8262333cc 100644
--- a/Assets/VRM/UniVRM/Editor/Tests/VRMBlendShapeKeyTest.cs
+++ b/Assets/VRM/UniVRM/Editor/Tests/VRMBlendShapeKeyTest.cs
@@ -12,16 +12,31 @@ namespace VRM
         {
             var key = new BlendShapeKey("Blink", BlendShapePreset.Blink);
 
-            Assert.AreEqual(key, new BlendShapeKey("blink"));
+            Assert.AreEqual(key, new BlendShapeKey("Blink", BlendShapePreset.Blink));
             Assert.AreEqual(key, new BlendShapeKey(BlendShapePreset.Blink));
             Assert.AreEqual(key, new BlendShapeKey("xxx", BlendShapePreset.Blink));
 
             var dict = new Dictionary<BlendShapeKey, float>();
-            dict[new BlendShapeKey("xxx", BlendShapePreset.Blink)] = 1.0f;
+            dict[key] = 1.0f;
 
-            Assert.IsTrue(dict.ContainsKey(new BlendShapeKey("blink")));
+            Assert.IsTrue(dict.ContainsKey(new BlendShapeKey("Blink",BlendShapePreset.Blink)));
             Assert.IsTrue(dict.ContainsKey(new BlendShapeKey(BlendShapePreset.Blink)));
             Assert.IsTrue(dict.ContainsKey(new BlendShapeKey("xxx", BlendShapePreset.Blink)));
+            
+            dict.Clear();
+            
+            var key2 = new BlendShapeKey("Blink"); // name: Blink, Preset: Unknown
+            dict[key2] = 1.0f;
+            
+            Assert.AreEqual( key2, new BlendShapeKey("Blink", BlendShapePreset.Unknown));
+            Assert.AreNotEqual(key2, new BlendShapeKey("blink"));
+            Assert.AreNotEqual(key2, new BlendShapeKey("Blink", BlendShapePreset.Blink));
+            Assert.AreNotEqual(key2, new BlendShapeKey(BlendShapePreset.Blink));
+            
+            Assert.IsFalse(dict.ContainsKey(new BlendShapeKey("blink")));
+            Assert.IsFalse(dict.ContainsKey(new BlendShapeKey("Blink",BlendShapePreset.Blink)));
+            Assert.IsFalse(dict.ContainsKey(new BlendShapeKey(BlendShapePreset.Blink)));
+            
         }
     }
-}
+}
\ No newline at end of file
diff --git a/Assets/VRM/UniVRM/Scripts/BlendShape/BlendShapeKey.cs b/Assets/VRM/UniVRM/Scripts/BlendShape/BlendShapeKey.cs
index 7ef55541e..7a2f63a75 100644
--- a/Assets/VRM/UniVRM/Scripts/BlendShape/BlendShapeKey.cs
+++ b/Assets/VRM/UniVRM/Scripts/BlendShape/BlendShapeKey.cs
@@ -1,15 +1,34 @@
 using System;
-
+using System.Collections.Generic;
 
 namespace VRM
 {
     [Serializable]
     public struct BlendShapeKey : IEquatable<BlendShapeKey>, IComparable<BlendShapeKey>
     {
-        public string Name;
+        /// <summary>
+        /// Enum.ToString() のGC回避用キャッシュ
+        /// </summary>
+        private static readonly Dictionary<BlendShapePreset, string> m_presetNameDictionary =
+            new Dictionary<BlendShapePreset, string>();
+
+
+        /// <summary>
+        ///  BlendShapePresetと同名の名前を持つ独自に追加したBlendShapeを区別するためのprefix
+        /// </summary>
+        private static readonly string UnknownPresetPrefix = "Unknown_";
+
+        private string m_name;
+
+        public string Name
+        {
+            get { return m_name.ToUpper(); }
+        }
+
         public BlendShapePreset Preset;
 
         string m_id;
+
         string ID
         {
             get
@@ -18,42 +37,56 @@ namespace VRM
                 {
                     if (Preset != BlendShapePreset.Unknown)
                     {
-                        m_id = Preset.ToString().ToUpper();
+                        if (m_presetNameDictionary.ContainsKey(Preset))
+                        {
+                            m_id = m_presetNameDictionary[Preset];
+                        }
+                        else
+                        {
+                            m_presetNameDictionary.Add(Preset, Preset.ToString());
+                            m_id = m_presetNameDictionary[Preset];
+                        }
                     }
                     else
                     {
-                        m_id = Name;
+                        m_id = UnknownPresetPrefix + m_name;
                     }
                 }
+
                 return m_id;
             }
         }
 
-        public BlendShapeKey(string name) : this(name, BlendShapePreset.Unknown)
+        public BlendShapeKey(BlendShapePreset preset) : this(preset.ToString(), preset)
         {
         }
 
-        public BlendShapeKey(BlendShapePreset preset) : this(preset.ToString(), BlendShapePreset.Unknown)
+        public BlendShapeKey(string name, BlendShapePreset preset = BlendShapePreset.Unknown)
         {
-        }
-
-        public BlendShapeKey(string name, BlendShapePreset preset)
-        {
-            Name = name.ToUpper();
+            m_name = name;
             Preset = preset;
+
             if (Preset != BlendShapePreset.Unknown)
             {
-                m_id = Preset.ToString().ToUpper();
+                if (m_presetNameDictionary.ContainsKey((Preset)))
+                {
+                    m_id = m_presetNameDictionary[Preset];
+                }
+                else
+                {
+                    m_presetNameDictionary.Add(Preset, Preset.ToString());
+                    m_id = m_presetNameDictionary[Preset];
+                }
             }
             else
             {
-                m_id = Name;
+                m_id = UnknownPresetPrefix + m_name;
             }
         }
 
         public override string ToString()
         {
-            return ID;
+            return ID.Replace(UnknownPresetPrefix, "").ToUpper();
         }
 
         public bool Equals(BlendShapeKey other)
@@ -65,7 +98,7 @@ namespace VRM
         {
             if (obj is BlendShapeKey)
             {
-                return Equals((BlendShapeKey)obj);
+                return Equals((BlendShapeKey) obj);
             }
             else
             {
@@ -84,6 +117,7 @@ namespace VRM
             {
                 return default(BlendShapeKey);
             }
+
             return new BlendShapeKey(clip.BlendShapeName, clip.Preset);
         }