Apparently her best friend's son Yuta's grades aren't improving. Eri comes to her for advice, worried that he's not studying properly despite being a high school student preparing for entrance exams. Deciding to do something for her best friend, Eri immediately visits Yuta's room, but... there she finds Yuta masturbating with complete concentration. Thinking that if she can satisfy his sexual desires, he will be able to concentrate on his studies, Eri promises him, "If he works hard, I'll have sex with him."