A teenager discovers that he is an Ajin and flees before the authorities experiment on him. Other Ajin plan to fight back and he must choose a side.

Twelve-year-old Gon Freecss one day discovers that the father he had always been told was dead was alive and well. His Father, Ging, is a Hunter—a member of society's elite with a license to go anywhere or do almost anything. Gon, determined to follow in his father's footsteps, decides to take the Hunter Examination and eventually find his father to prove himself as a Hunter in his own right. But on the way, he learns that there is more to becoming a Hunter than previously thought, and the challenges that he must face are considered the toughest in the world.