It seems that the grades of his best friend's son, Yuta, do not improve easily. Eri was consulted when she was worried that she was studying properly even though she was an examinee. Eri decides to take off for her best friend, but immediately visits Yuta's room. What I saw there was Yuta, who was indulging in masturbation. Eri, who thought that she could concentrate on her studies if she satisfied her naughty desires, promised that she would do her best if she did her best.