My father-in-law, who has started to develop dementia, mistakenly kisses my wife Satsuki, thinking she is his deceased wife. Her husband is also troublesome, so he leaves his father's care entirely to Satsuki. Satsuki had no choice but to take care of her father-in-law. Due to his dementia, he becomes violent and forces Satsuki to suck his penis. Gradually, Satsuki begins to find this relationship endearing and starts to lick his penis deliciously. At that moment, her husband, who had returned home from work early, found them.