Dear Chiharu,
Please click here to review my analysis of your buggy whip forehand. The lesson recommended to study is:
https://members.tennisevolution.com/topics/running-forehand-6/
The drill assigned to practice is:
https://members.tennisevolution.com/topics/running-forehand-crosscourt/
Keep up the great work!
Herman Krackow,
Head Coach