Hi Chiharu,
Please click here to review my analysis of your buggy whip forehand. The lessons recommended to review are:
https://members.tennisevolution.com/topics/inside-out-inside-in-2/
https://members.tennisevolution.com/topics/where-do-i-go/
https://members.tennisevolution.com/topics/dont-rush-it/
Herman Krackow,
Head Coach