In the 10th year of their marriage, Ryo's marriage has become cold. One day, she is approached by a man she doesn't recognize on the street. The man is Haneda, a childhood friend who had a crush on Ryo 20 years ago. He has grown into a handsome, strong man, with no trace of his former self. Then, while her husband is out, Haneda comes to visit in the rain and Ryo lets him use the shower, and by chance, she sees his private parts. Ryo loses her mind when she sees Haneda's large penis, which is completely different from the small one she saw when they bathed together as children...