Miki's life was pretty ordinary until the day her parents told her they were swapping spouses with another couple! Thanks to this unconventional arrangement, Miki not only gains two new step-parents, but a hot new step-brother, Yuu! At first Miki writes Yuu off as a total jerk, but as the two spend time together, Miki starts to fall for him. Can Miki sort out her complicated feelings for her Yuu?