A young mother kills a stranger in a fit of unexplainable rage. An inquisitive detective obsesses over the case, attempting to get to the bottom of the true motive behind the act.
Akira Fudo learns from his best friend Ryo Asuka that demons will revive and reclaim the world from humans. With humans hopeless against this threat, Ryo suggests combining with a demon. With this, Akira becomes Devilman, a being with the power of demon but with a human heart.