Sumire is dating Yosuke with the intention of getting married. She asks Yosuke to introduce her father and when she goes to her house, there is a former partner of her dad. Sumire's father suggests that the three of them move in together, but Sumire accepts the idea, fearing that if she offends him, he will reveal her father's activities. One day after they started living together, Yosuke had an urgent job.