When Akira Fudou, known for his gentle nature, reconnects with his childhood friend Ryou Asuka, he is thrust into a chilling revelation: demons are real and poised to seize control of the world. Driven by a desire to aid humanity, Akira agrees to merge with a demon at the infamous Black Sabbath gathering. Through a perilous fusion with the feared demon Amon, he transforms into Devilman, wielding Amon's might and Akira's compassion. Empowered by this union, Akira embarks on a mission to battle the demonic forces threatening to annihilate civilization, determined to avert humanity's tragic fate.