The story of Raji: An Ancient Epic begins with the start of a new war between the demons and the gods. Seeking to avenge their defeat in the last great war from a thousand years ago, the demons have challenged the gods who humiliated them and have invaded the human realm, threatening them with extinction.
Thinking that their enemies had been utterly defeated in the last great war, a thousand years ago, the humans had fallen into a false sense of security, forgetting the ways of alchemy, while enjoying the peace. Unable to defend themselves, cities and fortresses fell, leaving the humans at the mercy of the demons.