While his wife was away on a two-day trip with a friend, her husband Shota was at his wit's end with the mess in the living room. Just as he was thinking about cleaning up, his wife's sister Momoha suddenly came to help with the housework. Shota was grateful to Momoha for taking care of all the housework, but Momoha's real purpose was to relieve her sexual frustrations on Shota. Not knowing this, he was taking a carefree bath when Momoha came in...