Things get out of control at the Chronos syndicate and three of their secret experimental G-units are stolen. They dispatch a special combat unit of biobeast soldiers with instructions to recover the units at all costs. They are able to recover one of the devices. A normal high school student, Fukamachi Sho finds and activates the 2nd device, which transforms him into Guyver, a powerful living suit of Bioboosted Armour. And the 3rd device strangely goes missing.
Descriptions taken from AniDB.net