A beautiful mother, Hikaru, who has bigger breasts than her daughter, comes to live with her daughter and son-in-law. Hikaru is always around, taking care of her daughter and son-in-law, but her son-in-law, Yuta, is so attracted to Hikaru's sex appeal that he loses interest in having children. One night, as Yuta is about to go to the bathroom, he hears lewd voices coming from the bathroom. He slowly peeks in and finds Hikaru masturbating. Excited, Yuta spies on Hikaru's voluptuous body and has a certain desire...