Sho Fukamachi(深町 晶 Fukamachi Shō) is the main protagonist of the series, Shō is seventeen years old and a second-year student at Narisawa high school. As he is the host for the first Unit activated, he is known as "Guyver I".
He has black hair and a slim build.
He fights Kronos more in order to protect friends and family than from any need to see the enemy brought to justice. Had he not become host for a Guyver Unit, he probably would have happily continued in ignorance of Kronos.
He cares deeply for Mizuki Segawa with the intensity of first love and Tetsuro Segawa, Mizuki's older brother, is his closest friend. He had two other friends who tease him about his relationship with Mizuki named Takaya and Mono but they were killed.
Sho lived with his father, Mr. Fukamachi Until he was turned into a Zoanoid and was killed by his own son.
When he initially transformed into the Guyver, Sho was unconscious from the trauma of having the Unit forcibly bond itself to him. However, the Guyver itself was able to deal with the threat of the Zoanoids that had been disbatched to retrieve the lost Guyver Unit. Once Sho awakened from the fugue-like state that he had entered while bonding to the Unit, he was initially terrified of the armor that he found himself wearing, as well as its capacity for sheer destruction.
These feelings lead to him rejecting the armor, which in turn caused the armor itself to retreat from him and store itself in the sub-dimension that the armor resides in when not in use.
However, this was only a temporary reprive; the armor itself was still firmly bonded to him. Nothing short of the Unit Remover would be able to change that fact. Sho, however, was simply relieved to be free of the armor; he didn't know yet that he would not be able to get out of the situation so easily. When the next group of Chronos thugs confronted him - a pair of Ramotith lead by Guyver II in the 12 part OVA, and a group of Ramotith lead by a Vamore in the 2005 TV series and the manga - he was again able to call upon the Guyver to protect himself and his best friend, Tetsuro. In doing so, he discovered the most powerful of the Guyver's weapons: the mighty Mega Smasher; in the first two OVAs, he was also able to kill Guyver II at this point.
After that, Sho began to realize that the situation he was now in was very serious, and also, that there was far more to it than what he had seen so far.
From there, the stories follow two divergent, but related, paths.
Once Synevite made the mistake of taking Tetsuro for a hostage, Sho - having initially been severly battered by the long tentacles of the Zoanoid, and lacking a method to inflict more than superficial damage on the soft body of the squidlike Zoanoid - found new resolve, and with it, a way to use the Guyver's Vibration Blades.
Forced to fight for his life against Lisker, not even minutes after he had been brutalized by the Zoanoid Synevite, Sho was only able to escape from the vicious Chronos inspector thanks to a fortunate malfunction from Lisker's Control Medal. Returning with Tetsuro to the latter's house, Sho rested from his battle. He also wondered about what he had just seen; while he and Tetsuro waited for Mizuki to finish preparing dinner, Sho discussed his misgivings with his long-time friend.
Then, hearing a yell from Mizuki, Sho raced up to her room to see if he could give aid during what he likely thought was some kind of a struggle. However, this turned out to be something of a miscalculation on his part, leading to a great deal of embarrassment on both his and Mizuki's parts. He did, however, stand just outside her door while she regained her composure.
The Manga and OVA series
Lisker, having had extensive combat training as part of his pre-processing preparations for becoming a Hyper-Zoanoid, was easily able to get the upper hand on Sho. However, due to a timely malfunction on the part of Lisker's Control Medal, Sho was able to gain back the upper hand and kill him on the very same day he made his attack on the high school Sho, Tetsuro and Mizuki attended.
With Lisker dead, and even knowing what would befall him if his Control Medal were ever to be removed, Sho attempted to return to his normal life. His next day at school was rather placid, though not without some small annoyances along the way. Once they had finished the last of their work for the Sci-Fi Club, Sho and Tetsuro headed for their respective homes, clearly intending to walk together for as long as they could.
On their way home, Sho, curious about Agito since Mizuki had clearly taken an interest in him, began to question Tetsuro about the older boy.
Tetsuro, who had been close to the older boy some time ago, told him what he knew about Agito's past. Sho, who had grown up with a father, a mother, and a fairly normal life, was sympathetic to Agito's situation.
These moments of peace and reflection weren't to last, however; a small force of Zoanoids - numbering six in all, appeared just a few moments after Tetsuro had finished telling Sho about Agito's past. The two of them started running but Tetsuro, who lacked Sho's - by comparison - greater athletiscism, soon began to fall behind. Persued over the side of a steep embankment, Tetsuro and Sho were both siezed by the Zoanoids who had driven them to ground.
Sho called the Guyver without hesitation, causing his captor to lose his grip and be knocked backward. After disbatching the four Chronos Troopers that had come after them, both Sho and Tetsuro watched in stunned horror as three of them were killed by a sudden barrage of acid spray. As it turned out, this was the calling-card of the newest Zoanoid - a Hyper-Zoanoid named Zerebubuth - that Chronos had sent out in their latest effort to deal with him permanently.
At first, it seemed as if this latest effort of theirs was destined to succeed; Zerebubuth's armored carapace was impervious to Sho's punches, as well as resistant to his Head Beam. Zerebubuth was also equipped with bio-lasers on both arms, in addition to the three acid-dispensing tentacles on his head.
Sho was able to breach his carapace in the back with a powerful kick delivered with both legs. However, before he could capitalize on this newly-created weakness in Zerebubuth's armor, the Hyper Zoanoid spotted Mizuki, who had by extreme misfortune happened to be walking by. Leaping to the top of the embankment with a speed that belied his sheer size, Zerebubuth grabbed hold of her, intending to use her as a hostage.
However, while Sho himself was prevented from acting against the Hyper Zoanoid for fear of Mizuki's life, others were not so constrained. When Sho finally caught up, he found Mizuki safely on the ground, and a mysterious, darkly-armored figure crowned with six short spines. This, he soon came to realize, was the host of the third Guyver.
The next day started off rather normally, with a trip to school, and the work accomplished therein. Tetsuro thanked him for saving Mizuki from Zerebubuth, but Sho himself was of the opinion that it was his own involvment with her that had brought her into Chronos' sights in the first place. While this assesment was partially influanced by his own emotions, it would prove to be rather precient.
When he recieved a note from Chronos, challenging him to meet them at Mt. Narisawa, the very place where he had first come into contact with the Guyver, and also where he had killed his first Zoanoid. There was a certain poetic circularity to their choice of battleground, but it would only become obvious after the battle had finished; no one in-universe would notice it. Sho was determined to go alone to the site, but Tetsuro wouldn't hear of it, and with some doing convinced him not to.
When the two of them arrived at the site Chronos had chosen, they were confronted by Genzo Makishima. Stripped of his position as one of Chronos Japan's manigerial staff and - unknown to Sho and Tetsuro at the time - transformed into the prototype for the Guyver-killer Enzyme series, Genzo was quick to take the anger he felt at being so easily cast aside out on Sho. Transforming into the Zoanoid form he had been forcibly given, Genzo/Enzyme struck a devastating first blow: jamming his acid-secreting claws into Sho's chest, and this disabling the Mega-Smasher until the bio-armor could recover from the injury inflicted.
This, however, would take time; time was not on Sho's side in this battle.
With his Mega-Smasher damaged, Sho was left with only his melee weapons, something that would prove to be a severe hinderance when facing a creature like Enzyme; and also the later models that would come to bear that name. Hitting Enzyme's right shoulder with the Pressure Cannon, Sho was forced to dodge quickly as the Zoanoid whose later iterations would come to be known as the Guyver-killers swiped at him in retaliation. Enzyme's strength was great enough to both uproot and destroy the tree that he hit in place of Guyver I, causing it to snap like a twig.
Sho himself was the next to feel Enzyme's wrath; the Guyver-killer slashing him with claws and tail, leaving Sho with bleeding wounds on his arm, thigh, and head. However, while he had been fighting with Enzyme, the Guyver had been working to restore itself with a speed not seen in any other creature. Sho was surprised but pleased by this development, and would have obliterated Enzyme with his Mega-Smasher, if not for the fact that the Chronos agents disbatched by Richard Guyot to the site of their battle had managed to capture Tetsuro.
The Guyver and Guyver 2: Dark Hero (live action films)
Sean Barker is the live action counterpart of Sho Fukamachi. But does have major differences, such as his name, and not being Japanese. In the first film he was a college student and not a high school student, he is also part of a karate class. It's also different how he found and equipped the Guyver, he stumbled upon it at the location of Tetsu Segawa's death when he was killed by Lisker. After he takes it he gets himself caught in a fight with gangsters, while having the lower hand of the fight he accidently activates it and beats up all the gangsters. In the end of the film he kills Fulton Balcus by using his mega-smasher, him and Mizky then leave the Chronos building as lovers. He is portrayed by Jack Armstrong but is later replaced with David Hayter in the second film.
In the second film Sean becomes mentally tortured by his transformation into the Guyver, due of the fact that he's now brutally killing criminals on the streets, and doesn't know what to do with his power. Which also results in Mizky breaking up with him. He is drawn to an archaeological dig that turns out to be funded by Chronos. While there he falls in love with the leading lady of the film, Cori. He also meets another major character, Atkins, who works for the government, and Cori's father, Marcus. Later on, an alien ship is dug up. At the dig, Sean later learns that some of the people at the dig are Zoanoids who are being led by Crane, the main antagonist of the film. Cori's father also happens to be one. Later on everyone goes inside the ship, and Cori finds another Guyver Unit. Crane takes it planning to return it to Chronos HQ. Cori, overhearing of Crane's plan, is then took hostage by some of the Zoanoids and is about to be killed. Sean learning about this becomes the Guyver and saves Cori, slaughtering the two Zoanoids. Crane hearing that Guyver killed them, he instead equips the Unit to himself. Sean and Cori return to the dig planning to destroy the alien ship. Before thinking about destroying it, Sean goes inside the ship as the Guyver learning about the history of humanity and the purpose of the Guyver. While exiting the ship Cori and Atkins are held hostage by the Zoanoids. Cori's father comes in and frees them from their grasp. Cori then takes cover while Guyver, Atkins, and her father fight off the Zoanoids. Guyver and Atkins kill all the Zoanoids except for Crane who manages to kill Marcus. Crane then turns into the Guyver Zoanoid, who has a damaged control metal. Him and Guyver duke it out. Guyver starts losing against the Guyver Zoanoid, until Cori shoots the Guyver Zoanoid in the control metal causing his suit to malfunction. Guyver then rips off the damaged control metal causing him to liquify. Guyver then proceeds to use his mega-smasher to end his misery. After the Guyver Zoanoid's defeat, Guyver then makes the ship take off into space. They all get out of the dig. Atkins then asks Sean to help him and the government launch an underground war against Chronos. Sean refuses and drives away happily with Cori, ending the film.
Sean's problem where he inevitably killed criminals with his Guyver powers can be compared with Sho's whom had his Guyver killed his Zoaformed father against his wishes. The differences however, Sean had his Guyver killed thugs against his wishes when he still awake whereas Sho had his Zoaformed father tore half of his brain that render him lost consciousness, caused his Guyver possesses him and killed his Zoaformed Father in cold blood while restoring its host's fatal injuries. Reason how Sean had his Guyver's killer instinct get best of him may have something to do with when his control Medal attacked by Zoanoids in first film where they hit it first before tore it from his head. Control Medal of a Guyver was meant to supressed the unit from eating the host as well as allowed the unit's semi-sentience taking over the body as mindless killing machine to protect him/her from perceived threats should the host suffer a fatal wounds that made him/her lost consciousness. The attack on Control Medal of Sean's Guyver during events of the first movie may caused his Guyver's semi-sentience surfaced onto his mind in form of urge to kill that he had to struggle with whenever he wore his Guyver armor around his enemies, resulting him unknowingly fatally wound criminals that he fought against.