Growing increasingly frustrated with her stagnant married life, Reiko (Reiko Sawamura) ends up having an affair with her son. If it is discovered, her family will fall apart in an instant. She must keep this secret for the rest of her life... But the moment her husband gets into the bath, Reiko feels her crotch heat up. While her husband is taking a bath, she has 15 minutes to be alone with her son without him finding out. If only she could... She turns around to see her son looking at her with excitement.