The Nishio couple live an ordinary life in an apartment in a quiet residential area. One day, they see their big-dick househusband, Omachi, who lives next door, cleaning the front door with strange movements. He calls it "housework exercises" and says that you can get in shape while doing housework. Kaori is intrigued and immediately decides to let him show her how to do them. At first, it's a serious lesson, but gradually she starts to feel horny...