A son-in-law who is addicted to an immoral and sensual life with his mother-in-law, who has a body that is sexier than his wife's! When his wife is hospitalized, her husband is forced to live alone, and his wife's mother comes to Tokyo to help with the housework! The sexless and sexually frustrated son-in-law has been using his mother-in-law as masturbation material for a while. He comes up with a devilish plan to have sex with his defenseless mother-in-law, who sometimes flashes her panties while cleaning, and lets him stare at her cleavage and soft-looking buttocks...