Ayumi married her husband, who is far from old. As her husband's sexual desire declines year by year, Ayumi, young, has a tortured body. At that time, the Takanashi family ends up taking care of their nephew for a while while they were looking for a job. After meeting again after a long time, her nephew has become a truly adult man, and Ayumi ends up having unfortunate fantasies. After witnessing her nephew's masturbation scene, the two become so obsessed with a secret relationship that they end up having sex in the couple's bedroom.