Manga

The manga was originally published in the Kodansha's Magazine Z, from August 1999 (1999-08) issue to April 2004 (2004-04) issue.^[1]

OVA adaptation

On May 24, 2000, a loose adaptation of the first volume of Amon: The Darkside of the Devilman was released. Being based on volume 1 of the manga (no other volumes were released at the time), it is much shorter than the manga, and branches off in an entirely different direction shortly after Amon gains control of Akira Fudo at the end of volume 1.

In the OVA, fear runs rampant throughout Tokyo as paranoia grips the population who believe that demons exist among them. Akira is seen coming to the aid of Miko and Yumi, two female members of his team of demon hunters. Later, at Miki's home, her brother Tare watches a live broadcast video footage of Akira transforming into Devilman. Before he can tell Miki, a group of vigilante demon hunters corner and kill him. When Miki comes down the stairs, she is attacked and decapitated. Ryo Asuka goes on TV and stirs unrest and violence by warning people to be vigilant against demons. Later, Akira sees the group of vigilantes with Miki's head. He then loses control and transforms into Devilman and kills them all in a sea of blood. Akira is later informed by Yumi that the Devilman Army scout troops are combating a squadron of demons led by Seylos.

When Akira arrives, Selos gives Akira the option to join his army or die. Having lost control, Akira releases a wave of energy which destroys the building, with Amon left in his place. Selos' demons attack him, but Amon's overwhelming strength immediately grants him the upper hand, and he effortlessly defeats them one after the other. During a pause in the fight, Amon finds Yumi trapped under a piece of masonry. After seemingly rescuing her from the wreckage, he then suddenly takes a bite in her, eating on her and leaves her body in half while Seylos' remaining demons and Miko look on in terror. He then confronts Selos. The two demons engage in a citywide titanic battle but Amon is far too strong and kills Seylos after punching through his body. Amon then finds and attacks Satan who tells him that Akira still exists. Amon later confronts Akira in a wasteland. Akira then transforms into Devilman and they fight, but Amon seems far stronger and savagely beats Devilman. Semi-conscious, Devilman's mind drifts back to his life as Akira and time with Miki which gives him the strength to retaliate and defeat Amon. Devilman then fights back and delivers a rapid-fire barrage of right-hand punches which finally subdues Amon and ultimately finishing him off with a final blow, resulting in Akira successfully regaining control. The OVA ends with Akira Fudo and Ryo Asuka (who is Satan in his human form) facing each other before Akira begins to slowly walk past him.