diff --git a/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10Runtime.cs b/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10Runtime.cs
index 29182017f..a1bfd10cc 100644
--- a/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10Runtime.cs
+++ b/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10Runtime.cs
@@ -51,6 +51,11 @@ namespace UniVRM10
 
         public Vrm10Runtime(Vrm10Instance target, bool useControlRig)
         {
+            if (!Application.isPlaying)
+            {
+                Debug.LogWarning($"{nameof(Vrm10Runtime)} expects runtime behaviour.");
+            }
+
             m_target = target;
 
             if (!target.TryGetBoneTransform(HumanBodyBones.Head, out m_head))
diff --git a/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10RuntimeLookAt.cs b/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10RuntimeLookAt.cs
index f2fec3410..d72ecf54b 100644
--- a/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10RuntimeLookAt.cs
+++ b/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10RuntimeLookAt.cs
@@ -96,8 +96,6 @@ namespace UniVRM10
 
         private static Transform InitializeLookAtOriginTransform(Transform rawHead, Transform actualHead, Vector3 eyeOffsetValue)
         {
-            if (!Application.isPlaying) return null;
-
             // NOTE: このメソッドを実行するとき、モデル全体は初期姿勢（T-Pose）でなければならない。
             var lookAtOrigin = new GameObject("_look_at_origin_").transform;
             lookAtOrigin.SetParent(actualHead);
@@ -108,19 +106,19 @@ namespace UniVRM10
         }
 
 #region Obsolete
-        [Obsolete]
+        [Obsolete("Use " + nameof(LookAtOriginTransform))]
         public Transform GetLookAtOrigin(Transform head)
         {
             return LookAtOriginTransform;
         }
 
-        [Obsolete]
+        [Obsolete("Use " + nameof(SetYawPitchManually))]
         public void SetLookAtYawPitch(float yaw, float pitch)
         {
             SetYawPitchManually(yaw, pitch);
         }
 
-        [Obsolete]
+        [Obsolete("Use " + nameof(Yaw) + " & " + nameof(Pitch))]
         public (float, float) GetLookAtYawPitch(
             Transform head,
             VRM10ObjectLookAt.LookAtTargetTypes lookAtTargetType,