Chiaki is happy to hear that her daughter Eri has a boyfriend. Her boyfriend, Hayato, is a polite and kind young man, and Chiaki is attracted to his personality. One day, Chiaki witnesses Eri and Hayato flirting and gets excited and indulges in masturbation in her room. Chiaki begins to worry about Hayato, and when Eri is not around, she takes the plunge and approaches Hayato.