Hikaru Shidou, Umi Ryuuzaki, and Fuu Hououji are strangers brought together by fate when they meet during a seemingly normal field trip to Tokyo Tower. Accompanied by a great flash of light, they hear a mysterious woman's plea to save "Cephiro," and the junior high heroines are suddenly swept away by a giant flying fish. Afterwards, they arrive in an unknown land, where they encounter a man called Master Mage Clef. Clef informs the girls that they were summoned by Princess Emeraude to fulfill their destinies as Magic Knights, restoring peace and balance in Cephiro. The formerly lively and peaceful land has been in disarray ever since High Priest Zagato imprisoned the princess, who acted as Cephiro's pillar of stability. The Magic Knights reluctantly accept Clef's words as truth and embark on a journey to save Cephiro from the clutches of evil. [Written by MAL Rewrite]

Soon after Hikaru, Umi, and Fuu return to Tokyo, the three of them meet at Tokyo Tower to talk. Hikaru says that she wishes they could return to Cephiro and do something good for the land that Princess Emeraude protected so dearly. Umi and Fuu agree. Suddenly, a light appears in the sky and they are transported to Cephiro. Clef explains to them that with no Pillar to keep Cephiro peaceful, it has fallen into chaos. Monsters are multiplying and the land is becoming desolate. All the remaining inhabitants of Cephiro have moved into a magical castle. Clef also tells the girls some alarming news; three other countries, Chizeta, Fahren, and Autozam are trying to invade Cephiro and take over the Pillar system for their own purposes. The girls must stop the invaders as well as the mysterious and evil Lady Debonair, who believes she is the rightful Pillar, all the while desperately hoping and searching for a new Pillar to make Cephiro into the beautiful land it once was. (Source: ANN)

There is a small village called Jimuna on the continent of Jamu Jamu. This village is home to a girl named Kukuri. She is the last descendant of the Migu Migu Tribe. She is raised by an old witch who teaches her the secret magic of the tribe, but Kukuri is not a good student. In the same village lives a boy named Nike. He has been raised by very strict parents. They discipline their son to become a brave hero of the village. Nike himself does not want to be a hero at all, but he grows up to become a mighty boy. One day the king of the village, Kodai, recruits troops to fight against the ruler of the darkness, Giri. Kukuri and Nike are accepted. The two children, the strong but reluctant hero Nike, and the eager but unskilled little witch Kukuri, set out on a wonderful journey full of adventures and friendship. (Source: Nippon Animation)

As the mermaid princess of the North Pacific (one of the seven mermaid kingdoms), Lucia entrusts a magical pearl to a boy who falls overboard a ship one night. Lucia must travel to the human world to reclaim her pearl and protect the mermaid kingdoms. Using the power of music Lucia is able to protect herself and the mermaid kingdoms from a growing evil force.