Mysterious immortal humans known as "Ajin" first appeared 17 years ago in Africa. Upon their discovery, they were labeled as a threat to mankind, as they might use their powers for evil and were incapable of being destroyed. Since then, whenever an Ajin is found within society, they are to be arrested and taken into custody immediately. Studying hard to become a doctor, Kei Nagai is a high schooler who knows very lit...