For Umi, Fuu and Hikaru, the tranquil beauty of springtime in Tokyo is not met with their normal enthusiasm, they've graduated and the unwelcome prospect of attending different high schools threatens to break up their friendship. The girls make a wish to remain together, whilst beneath an enchanted cherry tree they quickly find their friendship tested in much more demanding ways than they ever expected. Mokona, the fairy residing within the legendary tree, has chosen the three friends to defend the Earth in a battle against extra-dimensional forces threatening to consume the planet. But they are not alone in their struggle, with the guidance of Clef, a rogue priest. Lexus, the first of three ancient allies duty bound to aid the girls. Hikaru, must protect her friends from the assault of Cephiro's ice-witch Alcyone. But despite her best efforts, the castle of Cephiro has broken into our World. It now stands brooding and evil in the centre of a lifeless Tokyo. Lantis forces Hikaru to prove her worth, sealing her into a magical maze from which she can only watch as Umi and Fuu are hunted down by Ferio the insect master and the child-warlock Ascot, who have been ordered to destroy the Knights before they can realize their destiny and threaten Cephiro's invasion plans. Fleeing through the silent city, Fuu and Umi must seek out the sleeping Mashin; a godlike creature that will fuse with them to form giant warriors of awesome destructive power. But the Magic Knights are afraid, untrained and alone.. will Mashin be enough to save them? The final battle for the survival of Earth has begun, aided by the spirits of the dead Eagle attacks Lantis and Ferio and launches a massive assault against the Magic Knights, wielding dark energies drawn from the castle of Cephiro itself. Eagle has sworn to destroy the girls and to kill and kill until nothing in the universe remains. His only goal is complete destruction - can even Rayearth, the awesome combination of all three Magic Knights and their spirit beasts prevent the murder of two entire worlds.