Seventeen years ago, immortals first appeared on the battlefields of Africa. Later, rare and unknown forms of immortal life began to emerge among humans, and they became known as "Ajin" (demi-humans). Just before the 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 bounty is placed on his head. Thus begins the life of a boy on the run from all of humanity.