Seventeen years ago, a group known as Ajin, comprised of divine warriors and demi-humans, appeared on African battlefields. They are believed to be an extraordinary discovery due to their immortality, but there are rumors that they have been subjected to inhumane experimentation.
Kei Nagai, an indifferent high school student with aspirations of being a doctor, yearns for a simple life until a catastrophic car accident changes everything. After regaining consciousness, Kei is accused of being an Ajin by witnesses who leave him with no means of proving his innocence. With the government in pursuit, Kei must evade them to stay alive. However, Kei is contacted by a group of rebellious Ajin, and he finds himself thrust into their struggle against government tyranny. Deciding which side to join in the human-Ajin conflict is Kei's biggest obstacle.