Every night, Mari's groin ached at the intense moans she heard and the passionate, animal-like mating of flesh against flesh. Even though her father-in-law is old, he is a sexual prodigy, and makes love to her mother-in-law every night. He is a viper-man who will remain active his whole life. In comparison, her husband is indifferent when it comes to sex. The frustrated wife's Kokoro gradually turns to her father-in-law. She wants to be held by her father-in-law as violently as that. Unable to suppress her desire, Mari goes to her father-in-law on her dangerous day to be held by him...