Prologue: A gun battle takes place in Africa in which a single western soldier outguns many locals, no matter how many times he is killed. He is eventually felled by tranquilizer darts and removed in a U.S. Top Secret body bag. Later, in Japan, Kei Nagai is leaving school, lost in his thoughts, crossing the road, when he is hit and killed by a truck. Within moments, he begins to recover and discovers he is an immortal Ajin, the third in Japan. The bystanders and students realize it too and begin to see the opportunity to receive a large reward for his capture. In shock, Kei screams which immobilizes everyone, allowing him to escape. The police and Yu Tosaki of the government Ajin branch converge on the scene. Kei manages to meet up with Kaito, an old trusted friend, and they flee on his motorcycle.