Mugi Suzuhara was a normal teenager, until her beloved older sister disappeared. Shortly after, her parents died in a suspicious car accident after saying they had found her sister. Mugi tries to break into her sister's high school, Shoukei Academy, one of those super, super elite high schools, to find evidence, but is almost hurt by a guard dog when she's saved by Kazuya Midou, a rich and powerful student. He makes a deal with her that she can look around the school as a substitute teacher if she acts as a housekeeper for him and his three male boarders - who happen to also be very popular Shoukei students.

Includes the oneshot titled "Baby Love" (volume 1), "My Fiendly Robot" (volume 5) and "Fairy Tale" (volume 6).