In the land of Shuten lies a warring people, a country bearing a history of endless strife and conflict. Back then, it's people knew not of peace, all were constantly at odds for power and supremacy.

But one day, an individual bearing a deific and demonic aura stepped onto their shores, hieing from the ocean itself. This stranger possessed pointed horns, piercing eyes and great fangs.

They unleashed a storm of destruction with just their sword alone, bringing the endless war to a permanent cease and becoming it's ruler.

Warriors who bowed their head to this being were allowed to pledge an oath with creatures called oni in exchange for great power. Those were the Sunsworn.