On his way to school, Junichi Nagase saves a girl from danger. Later, due to a misunderstanding, he kisses her. Shocked and disgusted, and without understanding what just happened or why, she screams at him and tells him to "just die!" As it turns out, the girl, Yuuhi Katagiri, is a new transfer student and, much to the surprise of Junichi and his younger sister Minato, their father arranged for Yuuhi to be Junichi's future wife. Of course, getting married to "that perverted idiot" is the absolute last thing Yuuhi wants. Junichi's crazy school life with his tsundere bride-apparent has begun.