Ten years into a cold marriage, Yuki is approached on the street by a man she does not recognize. He is Samejima, the childhood friend who had a crush on her twenty years earlier, now grown into a handsome, muscular man. While her husband is away, he visits in the rain and she offers him a shower. A chance glimpse reveals that the tiny penis she remembers from their childhood baths has grown into a huge cock, and Yuki loses all restraint.