In a world where humans and demons coexist under a fragile peace, change is coming...A mysterious drug, known only as "Zone-00," seems to be causing demons all over Tokyo to lose control and revert to their old, violent ways. Enter two young students who stand on opposite sides of an ageless conflict. One a demon, the other an exorcist, they must now join forces to uncover the secret of "Zone-00" before it's too late!