Sean Barker became the unwilling host to an alien bio-armor known as the Guyver. A year ago he destroyed the Kronos Corporation, an organization of mutants who want the Guyver. Now he is trying to find why the Guyver unit forces him to fight and kill evil. He is lead to an archelogical site where scientists discover an ancient space craft. Now he must fight Kronos again before they discover the secrets of the Guyver's origin.