~~The following program contains adult themes and scenes of violence and sexual assault that may not be suitable for some viewers and is inappropriate for children. The content is intended for mature audiences only.~~

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...
In the old days, endless hordes 
of monsters ran rampant across the land.
في الأيّام الغابرة، عاثت قطعان لا تنتهي
من الوحوش فساداً في الأرض
Vor langer Zeit machten endlose
Horden von Monstern die Welt unsicher.
Antiguamente había demonios
sueltos causando estragos.
Antiguamente había demonios
sueltos causando estragos.
Autrefois, tu sais,
Un tempo, orde infinite di mostri vagavano
in modo incontrollato per il mondo.
No passado, um monte de monstro
causaram o caos neste mundo.
В давние времена мир разоряли
орды нечисти.