Three junior high school girls are summoned to Cefiro, a world full of monsters and magic, where it is foretold that they, as the Magic Knights, will save the realm from evil.

Clamp is an all-female Japanese manga artist group that formed in the mid-1980s. It consists of leader Nanase Ohkawa, who provides much of the storyline and screenplay for the group's works and adaptations. Clamp also includes three artists whose roles shift for each series: Mokona, Tsubaki Nekoi, and Satsuki Igarashi. Almost 100 million volumes of Clamp manga have been sold worldwide.