A modern world where despicable, maneating monsters are commonplace and no longer fiction, David Reece struggles to make use of his life, having a passionate mind but no alluring background. He wanders around aimlessly, feeling a subconscious thirst for a hunt that he cannot describe. He decides to volunteer in the U.S. Hunter Program, a branch of the Department of Defense Adverse Realm Control (ARC) agency, and licensed as a F-Rank Hunter after testing his probability with superhuman serum. On a hunting mission gone wrong, he becomes the unlikely heir of his own unexpected foe.