Ryo, a young professor returning from research abroad, takes his pure-hearted, crybaby friend Akira to a decadent party, where things turn demonic.
Akira has become a completely different man -- he's stronger and hungrier than ever before; he seeks out Ryo for answers.
After getting shut down by his editor, paparazzo Nagasaki gets desperate; Silene and Kaim learn what happened to their missing fellow demon, Amon.
Akira's mother calls and says she'll be home soon; everyone is looking forward to seeing her, but Ryo warns Akira not to trust any human.
Silene tracks down Amon, hoping to reawaken his demonic side, but in the ensuing battle the human soul of Akira remains powerful.
At a widely broadcast track meet, Ryo plans to expose high school athlete Koda as a demon, thereby spreading fear and distrust throughout society.
With the fear of demons gripping the world, humanity devolves into paranoia and violence; Akira tries to save other demon-human hybrids like himself.
Ryo's actions and motives remain a mystery to himself, so he revisits his past for answers; Miki's father searches for his missing wife and son.
Betrayed and exposed, Akira becomes a target; after Miki takes to social media to defend his human soul, she and Miko find themselves under attack.
Confronted by Akira, Ryo reveals the truth about demonkind and himself; humans, demons and devilmen gather for an ultimate battle for the world.