Yui was married to a kind husband and lived a happy life. But one day, her husband's father, who she hadn't heard from in a while, came to visit. Her husband resented his father for abandoning his mother and causing him so much trouble. However, with the encouragement of the kind Yui, who couldn't leave her father-in-law alone with nowhere to go, she decided to let him stay with her for a week. However, that was the beginning of her mistake...