Akira Fudo aprende do seu melhor amigo Ryo Asuka que os demos revivirán e recuperarán o mundo dos humanos. Cos humanos tendo a esperanza perdida fronte a esta ameaza, Ryo suxirelle a Akira combinar con un demo. Con isto, Akira converteuse en Devilman, un ser co poder dun demo pero co corazón dun ser humano.

Determined to protect his demon world from heavenly angels, demon Masatora Akutsu heads to earth in search of a charismatic human to rally his kin. Masquerading as a high schooler for his recruitment mission, he's captivated by the lovely Lily Amane. But he's in for a wild celestial surprise, because she's his archnemesis—an angel—and she's set on reforming his demonic ways!

A new guardian "angelus" uncovers a secret behind the Angelus System's bureaucracy that leads him to break its official rules about protecting humans.