She plans to go to Tokyo to see a concert, but her accommodations are fully booked, so she ends up staying at her sister's house. On the first night of her stay, Tsubasa watches her sister and her husband having an intense sexual encounter, and her sexless body throbs, leading her to masturbate. She is unaware that her brother-in-law is watching her. The next day, as soon as Tsubasa's wife goes out to work at her part-time job, her brother-in-law approaches Tsubasa. Even though she knows it's wrong, her sexless body is overwhelmed by his virility.