Panic and violence erupt in the streets when Ryou Asuka reveals that demons are disguising themselves as humans, in addition to those openly terrorizing humanity. Anyone who fails to hunt demons risks being violently killed. When Akira Fudou witnesses the aftermath of this happening to those he cares for, the delicate balance between his psyche and that of Amon—a demon he has fused with to fight back—is broken, allowing the powerful Amon to roam Earth once more. As Amon slaughters everything in its path, it remains unclear whether Akira will ever regain control.