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...

What have the Idaten been doing in the eight hundred years without any demons to fight? Where do they come from? What is their true nature? And what are they going to do when Dr. Obami plots their defeat?

With the presence of the demons revealed to the surviving Idaten, Dr. Obami sends one of his strongest warriors to challenge the peace-softened deities.

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.

Three battles are unfolding simultaneously as Ysley takes on General Piscalat of the Zoble Empire, Paula and Hayato tangle with Cory, the demon who looks like a child soldier, and Prontea toys with the powerful Neput. When the dust settles, how will the Idaten/demon conflict have changed?

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.

The Zoble coup d'etat comes to an end with the demons on the run and the Idaten on the hunt. But with so few demons left alive, and the razor-sharp witted Miku among them, can the Idaten find their remaining enemies and finish the fight?

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.

Miku suddenly appears in public and quickly the Idatens go after her to try and capture her, but something is wrong. Why would she appear in public right now?