Miki (Guangxi) Koishikawa is a typical high-school girl living with her kind parents. However when her parents go on a holiday, they meet the Matsura's. Mr Koishikawa falls in love with Mrs Matsura, Mr Matsura falls in love with Mrs Koishikawa and vice versa. Both couples decide to get a divorce and get remarried to their new love(s). The other couple has a son near Miki's age, Yuu (You). Neither parents wish to break up their familes, so they decide the most logical thing to do is for them to move in and live together. Despite Yuu being frustrating and annoying, Miki finds she has feeling for him. Her childhood friend (and old crush) Ginta is also seeking her affections.