Adu is no ordinary human being. He is actually one of the 12 most powerful Demon Kings who, after making a pact with an angel, has been allowed to materialize into a human's body in the real world under one condition:<br /><br />He must seek and destroy all of the other Demon Kings.<br /><br />Being one of the most powerful Demon Kings, this sounds like an easy task, but the aftereffect of becoming more human-like is becoming less demon-like. Becoming less powerful.<br /><br />This is the story of Adu's journey as he embarks on a quest to rid the world of the Demon Kings and protect its people, all while hiding his dark secret from the very people themselves.