The story is about three girls, Hikaru Shidou, Umi Ryuzaki, and Fuu Houji, who are on class field trips at Tokyo Tower, who are summoned by Princess Emeraude of Cefiro to her world, where they forego on a quest to become Magic Knights and save Cefiro. Guided on their journey by Mokona, a mysterious but cuddly creature, they meet friends and foes, learn more about each other and themselves.
