You’re a student, who discovers that you’re an "Ajin" when you’re fatally wounded in a traffic accident.

(In the world of Ajin, a small number of humans (termed "Ajin") possess immortality and extreme regenerative abilities that trigger upon death, allowing them to completely recover from any mortal injury in a matter of seconds. Ajin can also create "black ghosts", highly dangerous combat-oriented entities that are only visible to other Ajin. "Black ghosts" are resistant to physical injury, exhibit extraordinary physical strength, and have sharp teeth and claws. Different "black ghosts" have varying degrees of intelligence: most are completely reliant on their Ajin for directions, and others, such as yours, are more independent and likely to engage in self-initiated actions.)

Consequently, Ajin are considered dangerous and inhuman by the public, and most are captured by governments. Governments claim to protect Ajin, but in reality, most use them as subjects for cruel and inhumane experiments, as their abilities to completely recover from fatal wounds provides an unlimited source of organs and bodies in dangerous tests (such as live-fire weapons testing). As a result, Ajin that have escaped from government custody (such as Satou, the main antagonist) are bent on exacting revenge on governments.