Centuries ago, vicious and bloodthirsty demons who were immune to all manner of weaponry plagued mankind. Humanity's cries for help brought forth the Idaten; battle deities who would use their incredible speed to hunt the demons down, and then seal them away. In the following 800 years of peace, the Idaten have not had any enemies to fight. But that is about to change...

Rin is intent on wiping out the demons, but without a plan, it'd be too easy for some to escape. With that in mind, Ysley contacts another Idaten named Prontea to formulate a strategy, while the demons begin their own divide-and-conquer campaign against their divine enemies.

As Ysley and Prontea continue to plot their attack on the demons, Dr. Obami has the eagle-eyed Miku continue to evaluate the threat posed by the Idaten.

The invasion of the Idaten on the demon-occupied Zoble Empire reaches its climax, as Hayato battles against Emperor Takeshita while Rin confronts Empress Brandy.

It's been years since the coup d'etat on Zoble, and the demons have managed to remain hidden for that entire time, as the Idaten fruitlessly search for them. But when Miku springs her plan to rendezvous with the Demon Lord, all that is about to change.