Synopsis: While walking home from school, high school students Sh? Fukamachi and Mizuki Segawa accidentally discover one of three Bio Booster Armor units stolen from the Chronos Corporation. When Sh? and Mizuki are attacked by a Zoanoid, the unit comes into contact with Sh? and bonds with him, transforming him into Guyver I and promptly destroying the Zoanoid assailant. Meanwhile, a female Chronos agent named Valcuria acquires a second unit and becomes Guyver II. She then abducts Mizuki in order to challenge Sh? for the Guyver I unit.