Season 1

Kei Nagai is a good student whose life turned upside down when he was struck by a truck. After this accident he discovers that he is an immortal (ajin). Feeling shocked and panic, he runs away to an isolated place. Now he can't trust anyone but his childhood friend Kaito.

Tosaki takes the pursuit of government by Ajin. Kei and Kaito are attacked by bandits in search of rewards.

Kaito and Kei are seen and pursued by another motorcyclist. Meanwhile Yu Tosaki recognises Sato, an Ajin hunter at the original accident scene. The other motorcyclist causes the boys to crash, but Kaito recovers and knocks him unconscious.

Izumi fight against a being in Eriko's hospital room. After saying goodbye to Kaito, Kei receives a mysterious invitation.

Kei goes through horrible experiences in a government laboratory and Tanaka encourages you to free his dark side. Sato planning a rescue mission.

Sato starts killing people in the lab. Kei tries to stop him and discovers that Ajin has a weak spot.

With his job at stake, Tozaki takes drastic measures to find out more about Ajin. Sato takes his emphasis on putting into practice a new plan.

Ko flees after Fact reveals his evil plans. Who takes refuge to practice the invocation of his ghost.

Sato prepares to attack. Ko discovers the hideout of Kei and begs for help. Tosaki gets a surprise visit.

Tozaki make new discoveries. Neighbors Mrs. Yamanaka suspect Kei. Sato finalizes his plan.

In the supposed day of the attacks, the scenario of the city is shocking. Sato prepares for action with your team.

With the country all online assisted Tozaki employs a new tactic to deter Sato. Kei loses its disguise.

Mr Keita reports Kei Nagai to the police to claim a reward. Yu Tosaki orders all available forces to the area to catch Kei. When Kei is confronted by the police, he uses his Black Ghost to delay them allowing him to escape into the woods. He uses Ko Nakano’s phone to throw the police off his trail, but Tosaki realizes it's a ruse and closes in.