17 years ago, immortals first appeared on the battlefields of Africa. Later, rare, unknown new immortal lifeforms began appearing among humans, and they became known as "Ajin" (demi-humans). Just before summer vacation, a Japanese high school student is instantly killed in a traffic accident on his way home from school. However, he is revived, and a price is placed on his head. Thus begins a boy's life on the run from all of humankind.