Tomohisa married into the Maki family as an adopted son-in-law. His mother-in-law, Kyoko, is a beautiful woman who is admirable for her beauty and perfect housekeeping skills. However, one night, Tomohisa finds out that the two are a fake married couple due to his father-in-law's affair! Kyoko, who is still in her prime, gradually becomes frustrated, and Tomohisa pounces on her big breasts as if he had planned it! The son-in-law plays with Kyoko, who unintentionally gets aroused... Through embarrassing play and creampie sex at home, Kyoko falls into the role of a big-breasted adultery sex doll for his son-in-law...