Sho Fukamachi was an average student until the day he came into contact with a Guyver Unit, a bio-mechanical symbiote. Together, they became a superhuman entity and was forced to fight to protect his life and the lives of those he cares for.
Sho Fukamachi was raised by his father, Fumio Fukamachi, a widower. At age 17, Sho became a second-year student at Narisawa High. One day, Sho was walking with his friend Tetsuro Segawa when the two heard an explosion. They found a strange artifact that suddenly bonded with Sho. It transformed Sho into a bio-organic cyborg with considerable destructive power, as well as causing him to black out. He almost immediately encountered agents of Kronos, an organization that desired the artifact called the Guyver for their own evil ends. Sho almost immediately destroyed a strange mutant working for Kronos who threatened to destroy him and Tetsuro. He then reveals to Tetsuro he was unconscious throughout the fight and his body was acting on its own.