Once upon a time, a fine balance was maintained between humans and demons. Although there are occasional disagreements between the two sides, they still try to maintain the hard-won peace. Until the king of all demons, the "Nine-tailed Fox", emerged and led all the demons to wreak havoc on the mortal world. Embark on a journey in a chaotic world and fight against all kinds of demons. Find a way to restore peace through one adventure after another and gradually piece together the truth behind the mystery.