In a world where the air is polluted with radiation, a mutant is created by scientists to take back the world from mutated animals. However, a spark of courage and desire for adventure is found in the mutant when he meets a broken robot.

Zero, a robot that can use magic, and his partner in crime, Kent, a beast man, are taking mercenary jobs to live by. Until one of those jobs leads them to uncover Zero's origin. What kind of adventure is awaiting them?