Episodes 1-4 of the anime adapted from Yoshiki Takaya's long-running manga chronicles. In the future, a sinister multinational corporation has been creating bio-weapons, particularly Zoanoids - wild, vicious creatures with the ability to disguise themselves as humans. Also on the Chronos product line are Guyver units - suits of super armour that bond with the wearer making him impervious even to a Zoanoid attack. A high school student, Sho Fukamachi, and his portly pal Tetsuro find one of these suits during an escape attempt by a test subject. Testing it out, Sho is forced to protect himself and Tetsuro from attack and discovers the ease with which he can now tear enemies limb from limb without breaking sweat. Coming to grips with his newfound superpowers with clever Tetsuro's help, it soon becomes apparent that Chronos wants control of him. A second suit is bonded with a Chronos investigator to that end and worse, a third is bonded with Agito Makishima, a third-year at Sho's school and son of a Chronos exec.