Mrs. Ruo is completely sweet and charming in her ways.

Kouji, a associate professor at the university, has been married to Ai’s daughter, Sei (Makiko). It’s been two years since they got married, but Kouji still doesn’t find his sexual life satisfying. He becomes increasingly dissatisfied with Sei for not expressing her pleasure openly. Meanwhile, Sei meets Eimi (Shoko Kudo) at the reunion of their classmates. She is invited to a home party. But this party is nothing more than a pretext for having sex. Sei experiences sensations she has never felt before during that party…