diff --git a/Assets/VRM10/Runtime/Components/SpringBone/VRM10SpringBone.cs b/Assets/VRM10/Runtime/Components/SpringBone/VRM10SpringBone.cs
index ee75cabbe..f834791c5 100644
--- a/Assets/VRM10/Runtime/Components/SpringBone/VRM10SpringBone.cs
+++ b/Assets/VRM10/Runtime/Components/SpringBone/VRM10SpringBone.cs
@@ -8,9 +8,16 @@ namespace UniVRM10
     /// <summary>
     /// The base algorithm is http://rocketjump.skr.jp/unity3d/109/ of @ricopin416
     /// DefaultExecutionOrder(11000) means calculate springbone after FinalIK( VRIK )
+    /// 
+    /// Setup の Editor の都合から、VRM10SpringBone は MonoBehaviour にする。
+    /// Data置き場。Updateは使わない。
+    /// 
+    /// Springの根元のTranform (Joints.First()) に AddComponent して使う。
+    /// 
     /// </summary>
+    [DisallowMultipleComponent]
     [Serializable]
-    public class VRM10SpringBone
+    public class VRM10SpringBone : MonoBehaviour
     {
         [SerializeField]
         public string Comment;
diff --git a/Assets/VRM10/Runtime/Components/SpringBone/VRM10SpringBoneColliderGroup.cs b/Assets/VRM10/Runtime/Components/SpringBone/VRM10SpringBoneColliderGroup.cs
index 2fb4e3a58..149f59bde 100644
--- a/Assets/VRM10/Runtime/Components/SpringBone/VRM10SpringBoneColliderGroup.cs
+++ b/Assets/VRM10/Runtime/Components/SpringBone/VRM10SpringBoneColliderGroup.cs
@@ -7,7 +7,6 @@ namespace UniVRM10
     /// <summary>
     /// VRMC_node_collider
     /// </summary>
-    [DisallowMultipleComponent]
     [AddComponentMenu("VRM10/VRM10SpringBoneColliderGroup")]
     public class VRM10SpringBoneColliderGroup : MonoBehaviour
     {
diff --git a/Assets/VRM10/Runtime/IO/RuntimeUnityBuilder.cs b/Assets/VRM10/Runtime/IO/RuntimeUnityBuilder.cs
index f5c4dd71d..926e02826 100644
--- a/Assets/VRM10/Runtime/IO/RuntimeUnityBuilder.cs
+++ b/Assets/VRM10/Runtime/IO/RuntimeUnityBuilder.cs
@@ -353,7 +353,12 @@ namespace UniVRM10
             {
                 foreach (var gltfSpring in gltfVrmSpringBone.Springs)
                 {
-                    var springBone = new VRM10SpringBone();
+                    if (gltfSpring.Joints == null || gltfSpring.Joints.Count == 0)
+                    {
+                        continue;
+                    }
+                    var firstJointNode = Nodes[gltfSpring.Joints.First().Node.Value];
+                    var springBone = firstJointNode.gameObject.AddComponent<VRM10SpringBone>();
                     springBone.Comment = gltfSpring.Name;
 
                     // joint