Doress, a Japanese "black projects" organization, has been gathering psionics and making biological weapons to "make Japan superior". When one of the biological experiments, BAOH, escapes with a young girl, Doress will do anything to get the boy and girl back. For BAOH is a parasite living in its host's brain, altering the host into a living death machine in order to keep it alive. When Doress sends assassins after the boy and girl, BAOH "awakens" to its "Armed Defense Phenomenons", giving the boy acid-tipped claws, bio-regeneration, and super-strength. But Doress takes the girl, and BAOH must fight an army of commandos and a psionic to get her back.