Nanao is a housewife who lives while taking care of her husband and father-in-law. - Recently, her father-in-law's dementia has become so severe that he mistakes him for his late wife...However, the kind Nanao takes the role of his late wife and dedicates herself to caring for him. - However, Nanao's kindness becomes her enemy, and one day her father-in-law relentlessly demands her body! - Because Nanao understands her father-in-law's feelings, and also because of her own frustration, she ends up having a relationship with him... - Nanao and her father-in-law, who are not treated by their husbands, escalate their acts, and the two violently play with each other's bodies, immersing themselves in intense sex as if they were husband and wife.