Demons exist and their power is beyond what humans can fathom. In fact, they are so strong that humans do not stand a chance against them in a fight. The only thing strong enough to defeat a demon is another demon, and it is through this logic that Ryo Asuka hatches the plan to have his good-hearted friend, Akira Fudo, possessed by a demon. If a person is of pure of heart, then they might be able to contro...