<p>The series focuses on a group of teenage girls attending Lillian Catholic school for girls in Tokyo, Japan. A common theme throughout the series revolves around the lives and close relationships of the schools student council known as the Yamayurikai.

<p>Yumi Fukuzawa, who is basically a nobody and a first year student at Lillian Academy, a Catholic exclusive school for girls with a tradition that older girls take a younger girl as their little sister or "soeur," suddenly finds herself interacting with