Karuizawa Ryo is a third-year middle schooler who has a crush on a cute, smart, and popular girl named Omoi Miton. After hearing that Omoi is going to an all-girls high school, Karuizawa decides to confess his feelings to her. To his surprise, she agrees to date him! But... now what? Meanwhile, Omoi has everything planned from the get-go, including transferring to his high school, getting married in two years, and setting up insane rules for their relationship. Because of that, Karuizawa realizes what kind of a person Omoi truly is; a girl with an overwhelming obsession with relationships! Despite his concerns, their dating life begins, painting his high school life in a totally different color.