Touka is a housewife who lives with her husband, daughter and husband-daughter couple. She became pregnant with her daughter in her teens and was busy raising her child, so she and her husband have been estranged from each other since then. However, her son-in-law Kohei is strongly attracted to Touka's body! Her beauty is so strong that it's hard to believe she's a mother-in-law, and her big breasts are obscene... Living so close to Touka, Kohei's reason eventually collapses and he forcibly commits an affair in the family! "That person... I can't do it with that child...!" Touka refuses with words, but gradually she is filled with her son-in-law's strong sexual desire...