Eko is fighting and eventually kills a Karas. Three years later, Kure witnesses an attack on a film crew by a water demon and survives. He is sent to a new police department with Sagisaka and begins investigating the bizarre murders, which Sagisaka believes are perpetrated by youkai. He and his ally, Kure, are also hunting Nue, because they believe he may have something to do with the incident in the subway restroom. Meanwhile, demon hunter Nue is on the trail of Suiko. His assassination attempt is interrupted by the new Karas. Otoha enters and engages Suiko in combat, and easily kills him.

It is revealed that Sagisaka believes in youkai because his daughter, sole survivor of a brutal demon attack at her school, is one of the few who lived to tell about the demons. But she is hospitalized for mental/emotional problems caused by the demon attack, and her father is still waiting to get her testimony of the events. Kure and Sagisaka pursue Nue and run into the Mikura Wanyudo, which attacks them. Nue attacks Wanyuda, but is unable to kill him, and is injured before Otoha appears in Karas form and kills the Mikura off, with Nue forced to reveal his true Mikura form.

Nue and Otoha face off, and Yurine orders Otoha to kill him. Nue's yokai friend pleads for Nue's life, and Otoha is unable to bring himself to attack Nue because he feels that Nue isn't evil. Nue flees with a bad injury. Meanwhile, Eko and his minions move their plans forward; it is revealed that Eko is using another Yurine as a power source to create his mechanised Mikura demons. Two of his minions, Tsuchigumo and Kamaitachi attack the city and Karas is forced to fight Tsuchigumo miles away from where Kamaitachi was making his move. As Karas engaged Tsuchigumi, Yurine realizes that Eko's true target was actually Otoha's human body hospitalized, "comatose" human form. Karas's fight with Kamaitachi is cut short once he sees his true body. At that point, Yurine lets her guard down and is abducted by Tsuchigumo. Without Yurine's aid, Karas loses power and disappears. Before Kamaitachi kills Otoha, Nue appears and fights with Kamaitachi, but is so weak that he can't transform into a Mikura when he runs out of bullets. Otoha awakens from his coma and kills Kamaitachi while in human form. This all was witnessed by another Karas, a young lady named En.

With Otoha a human again, En decides to take remedial action as the new official Karas. Otoha, who saves the gravely injured Nue by giving blood, learns of the approaching cataclysm that Eko's working for. However, Nue advises Otoha to forget everything and resume his old life, with Nue intend to atone for the Mikuras' actions while saving his younger brother from Eko's grasp. Taking Nue's advice, Otoha returned to Kabukichou, where he finds his friend Reiji being held captive by the yakuza. Otoha kills his father, the yakuza boss, but Reiji dies in the fight.

With Otoha a human again, En decides to take remedial action as the new official Karas. Otoha, who saves the gravely injured Nue by giving blood, learns of the approaching cataclysm that Eko's working for. However, Nue advises Otoha to forget everything and resume his old life, with Nue intend to atone for the Mikuras' actions while saving his younger brother from Eko's grasp. Taking Nue's advice, Otoha returned to Kabukichou, where he finds his friend Reiji being held captive by the yakuza. Otoha kills his father, the yakuza boss, but Reiji dies in the fight.

With Otoha a human again, En decides to take remedial action as the new official Karas. Otoha, who saves the gravely injured Nue by giving blood, learns of the approaching cataclysm that Eko's working for. However, Nue advises Otoha to forget everything and resume his old life, with Nue intend to atone for the Mikuras' actions while saving his younger brother from Eko's grasp. Taking Nue's advice, Otoha returned to Kabukichou, where he finds his friend Reiji being held captive by the yakuza. Otoha kills his father, the yakuza boss, but Reiji dies in the fight.