Yuuri, a big-breasted mother-in-law who has the same birthday as her daughter-in-law. His son-in-law, Yoshinobu, gives Yuuri the erotic underwear that he should send to his wife. And when she sees Yuuri wearing the underwear and starting masturbation, Yoshinobu's desire tag comes off. "I'm really frustrated, mother-in-law ..." Yoshinobu relentlessly seeks Yuuri's huge breasts everywhere so that his family won't find him.
