When her husband is transferred, Mayuki has to live with her parents-in-law. Even though her father-in-law is an adult, he has an incredible sexual appetite and makes love to her mother-in-law every night. Night after night, she hears his moans. Mayuki's crotch aches as their bodies collide, passionate and animal-like, making her crotch ache. In contrast to her father-in-law, her husband is indifferent. With a strong sexual appetite and wanting to have sex every night, Mayuki's Kokoro gradually shifts to her father-in-law, who has an insatiable sexual appetite. With her desire to be held by her father-in-law growing, Mayuki seduces him herself on a dangerous day...