A Student named Kei Nagai, who discovers he is an "Ajin" when he is fatally wounded in a traffic accident. In the world of Ajin, a small number of humans possess extreme regenerative abilities that trigger upon death or mortal infury, allow them to completely recover from their woulds in a matter of seconds. Kei, who wants no part in the emerging Ajin-human conflict. Agree with Japanese govermental againts to fight against Satou in exchange for his freedom from government experimentation.

The war betwen Ajin terrorist Satou and Ajin Administrative Committee has been escalating with Satou declaring a public assassination attempt on 15 Ajin-related VIP, an action Satou calls "purging." The final confrontations between Ajin and the Japanese goverment, as well as between Satou and Kei Nagai, are about to begin.