Satoru lost his mother when he was young and is currently living with his father and his new wife: Kyoko. One day, Satoru witnessed his father and Kyoko having sex, and since then, he has started having trouble sleeping (and experiencing erectile dysfunction). Kyoko found out and tried to teach him sex education... However, in her eagerness to help, she went too far. Nagae will actually come there. And Machimura Kyoko is extremely seductive, what a performance.