Hikaru Shidou, Umi Ryuuzaki and Fuu Hououji are three high school girls who have only just met at Tokyo Tower when a plea for help pulls them into the magical land of Cephiro. There Guru Clef tells them that Princess Emeraude summoned them as the legendary Magic Knights. They cannot return home until they save Cephiro from the monsters troubling it and free the princess from the powerful Lord Zagato. To face him, they must revive the mysterious Rune Gods. Clef gives them armor and magic, then sends them to the weaponsmith Presea and the rabbit-like guide Mokona for their journey. The project marks the franchise's 30th anniversary and mixes fantasy adventure with magical girl and mecha elements.