Emi, his mother's best friend, has come to his house, fleeing from her husband with whom they have a completely cold relationship. She is staying at his house for a while, and is also consulting about her divorce. Tatsuya, who had never had any relationships with women before, is excited just by the idea of a beautiful woman living under the same roof. Out of curiosity, he peeks into the room where Emi is sleeping. There he sees Emi moaning lewdly as she pleasures herself. This is enough to ignite Tatsuya's lust...