Three girls, Hikaru Shidou, Umi Ryuuzaki, and Fuu Hououji, all 2nd grade junior high students at different schools, meet by chance on field trips to Tokyo Tower and are suddenly pulled into another world named Cephiro by a mysterious princess named Emeraude. There they meet the master mage Clef, who informs them they are the Magic Knights called there to save Emeraude, and sets them on a journey to save Cephiro itself. While fighting enemies sent to them by the High Priest Zagato, who has Princess Emeraude imprisoned, the girls learn magic and awaken the legendary guardians.

The story began publication in the monthly shojo manga anthology “Nakayosi“ (KODANSHA) in 1993. This work by CLAMP features the unlikely combination of shojo manga and the giant robot genre. The main characters have attributes of fire, water, and air, collect weapons and learn magic, growing stronger as they progress, creating a story that feels just like a fantasy RPG. An animated series was released in 1994, and the opening theme “Unyielding Wish“ by Naomi Tamura sold over one million copies. It was so popular she was invited to perform it at NHK Kohaku Uta Gassen (Red and White Song Battle). The tragic ending of the original series drew widespread attention, and the second series began with the three girls returning to Cephiro several months after they were sent back to Tokyo. The conclusion here was structured to stand as a counterpart to the first part, and ends on a memorable question posed to the reader. An original animated video was released in 1997, and several games were made for the Sega Saturn, Game Gear, SNES, and Game Boy.