Wasaki has been married for two years. Six months ago, she started living with her father-in-law, Tadao, and things were going well... but one day, Tadao fell ill with a slipped disc and fell ill... After that, every time Wasaki touches him as she cares for him, Tadao, who hadn't had sex since his wife passed away, unconsciously gets an erection. Wasaki, who is not having sex with her husband, can't take her eyes off her father-in-law's crotch, and they end up having sex under the pretext of caring for him... The two of them secretly feel frustrated. They spend their days passionately entwining their tongues in the afternoons when her husband is not around...