Hiroshi, a university student who has been dating his girlfriend for six months, visits her house and is captivated by the beauty of her mother. His friend Takuya, who is in the same club, is also captivated by the mother's gentle smile. That night, Hiroshi is staying over at her house, but when Kokoro can't fall asleep and leaves the room, he can't help but fall into forbidden sex as the mother clings to him. When Takuya finds out, he also makes a mistake...!