It's been a week since my wife got pregnant and went home. Kentaro enjoys living alone for the first time in a long time, but he begins to feel lonely in an unpopular and quiet house. At that time, my sister-in-law, Mio, came to see me. I welcomed Mio because I couldn't stand the loneliness, but ... Mio's real purpose was to get rid of her frustration with Kentaro. Kentaro is completely deceived and takes a carefree bath. Mio came in and said, "I'm going to wash my back."