Mizuki and her husband move in with his widowed father. Sexually frustrated by her sexless marriage and drawn to the lonely older man, she is alone with him while her husband is at work when he finally loses control, pins her down, and creampies her. Their physical chemistry proves irresistible, and the in-laws abandon guilt and reason to devour each other through repeated creampies. Living under one roof, they can no longer stop even with the risk of pregnancy.