It's already been a week since his wife got pregnant and went back to her hometown. Kentaro is enjoying living alone for the first time in a while, but he's starting to feel lonely in the quiet, deserted house. That's when his sister-in-law Mio comes to check on him. Unable to bear the loneliness, he welcomes Mio back, but her real purpose is to relieve her sexual frustration with Kentaro. Kentaro is completely fooled and is enjoying a relaxing bath when Mio comes in and says, "I'll wash your back."