Mai Takeshi was once the proud daughter of a noble Samurai family, alongside her twin brother Raiden. Their lives are sweet and peaceful up until ninja rain onslaught on their home. Killing their parents and orphaning the twins, but all is not lost. Mizuki their sixteen year old maid, fends off the ninja attack and brings them to safety using unknown powers. On their way to Shinto Academy the last safe sanctuary for children of the elements, Mizuki explains what had happened the night their parents were killed in front of them, telling them about the red ninja. They arrive and make friends only to find out that, not everyone is keen to welcome them, escpecially when they are partly responsible for the death of their commisioner.