After the world ended in the original Devilman, Akira Fudo is in hell, seeking the soul of his beloved Miki while at the same time Doctor Hell is beseeching the underworld for power in order to get his revenge upon the hated Mazinger. Akira sets in motion a chain of events that earn the enmity of Hades himself, who'll stop at nothing to avenge the slights Akira commits against him.