"Something only I can do...That is...What I must do!"
- ―Yuta Hibiki, before being given the Primal Acceptor, Restoration
Yuta woke up in his classmate Rikka Takarada's house, after passing out. However, he realizes that he had been affected with with amnesia and is unable to remember anything prior. She helps him get back to his normal life with the aid of Sho Utsumi, another friend of his. When the monster Ghoulghilas appears, Yuta manages to navigate back to Gridman and reconnect with him to face the monster threat together with his friends.
While investigating the disappearance of their classmates who actually died in Ghoulghilas' attack the day before, Yuta was called back by Gridman to face another monster. Accepting that he had a mission, Yuta transforms into Gridman to fight against the incoming monsters.
One week later, he and Utsumi notice Rikka's absence from school so Utsumi gets him to (accidentally) call her but she doesn't pick up. Utsumi also points out, as a joke, that the kaiju they have been fighting against may actually be humans, though that unsettles Yuta. When Anti appears, Yuta is hesitant to fight when Anti talks, which reminds him of what Utsumi said earlier. This allows Anti to defeat Gridman easily. Gridman, Samurai・Calibur, and Yuta seemingly disappear. Utsumi almost disbands the Gridman Alliance the next day but was stopped by the timely arrival of the Neon Genesis Junior High Students, who said that Gridman, Calibur and Yuta were alive. Getting a hint, Rikka calls his phone, which he is somehow able to answer. After they returned, Gridman fought Anti with the help of Battle Tracto Max. After he wins the battle, Yuta gets slapped by Rikka, who then apologizes for not picking up his call earlier. After hearing that Rikka would be going on a group date, he gets jealous and decides to stalk her and her group but later loses them. Max approaches him and gets him to admit his feelings to Rikka and after the next kaiju attack, he asks Rikka out for a meal but she invites the rest of the gang as well.
While sleeping on a train, Yuta dreams of what seems to be Alexis・Kerib impaling Gridman with a spear and a star splitting into five. He later meets Anosillus the 2nd, who explains to him the nature of Tsutsujidai city, the Illusion Monsters and who Akane Shinjo really is. At school, Yuta tries to explain to Rikka and Utsumi as well, but they did not believe him due to how far-fetched his story seemed to be. Yuta was also chased down by Anti at school, demanding that he transform and fight, but Yuta replied by saying that Gridman would only come if there was a kaiju around, making Anti leave with the Special Dogs he just bought. Returning home after school, he finds Akane sitting on his bed and she tries to tempt him into joining her. Yuta declines, saying that he has friends to protect. Akane then demands that he walk her home and unable to decline, does just that. On the way, they stopped for dinner at the Chinese restaurant where he and his friends were looking for the deceased Tonkawa after Ghoulghilas' attack. He was then introduced to Alexis, who arrived late. With the Primal Acceptor flashing, Yuta went back to Junk to transform into Gridman and during his fight, he saw what seemed to be a city in the sky. Only after that did Rikka and Utsumi start believing what he said about Akane.
As the day of the school's Culture Festival drew closer, Yuta, Rikka and Utsumi decided to confront Akane directly and she shows off her newest kaiju, Mecha Ghoulghilas, and dares the trio to try to stop her, confident that they would fail. Seeing not much choice other than to fight, Yuta and Utsumi come up with a plan which was to make Gridman and the Assist Weapons sortie at only half their size so that they can all fight together. However, Rikka cannot bring herself to fight her friend. This sparks an argument between Rikka and Utsumi, with Yuta and Gridman being on middle ground. Understanding Rikka's feelings, Yuta and Utsumi try to persuade Akane into not unleashing Mecha Ghoulghilas, so that they may have a peaceful resolution, but she disagrees. Seeing Rikka upset on the way back to the Junk Shop, Yuta cheers her up by telling her of her contributions to the team and, hearing that she was going to apologize to Utsumi before he does to her, he gets an idea, which was to summon Gridman before the kaiju appears, to prompt an evacuation of the school. The next day, Yuta executed both plans successfully, and easily defeated Mecha Ghoulghilas as Full Powered Gridman. After that, he dressed up in a sailor outfit for the school Culture Festival.
Yuta was trapped in a dream during Bujack's attack, wherein history was rewritten so that the monster attacks never happened and all of Akane's desires were fulfilled. Yuta woke up with amnesia, and the events of the first episode repeat but with Akane replacing Rikka, who even claimed to be his girlfriend. The two of them spend time together but throughout, Yuta could feel Gridman's influence. Arriving at a graveyard, Yuta saw a gravestone for the Tonkawa family, which reminded him of his mission and after that, he rejects Akane's offer to be with her in the dream world. Yuta remembers the events that happened in reality and rush over to Rikka and Utsumi, and then Gridman wakes the three of them up. After reawakening, Yuta states that one more person must wake up from their dream - Akane Shinjo.
After hearing what Rikka has to say, Yuta comes up with the idea of going next door to Akane's house to confront her. Akane does not answer the doorbell, so Max forces the door open. Inside the "house", Yuta sees something similar to the city in the sky. As the days pass without kaiju attacks, Yuta starts to worry about Akane, who had been missing from school. After Gridman fights against another kaiju, Yuta apporaches Akane, who had seen him transforming, to tell her that she is simply being used by Alexis. Upon getting closer, Akane unexpectedly stabs him with her yellow cutter. Yuta bleeds out and, unable to call an abulance for some reason, Rikka's mother brings him to the hospital in her van. Yuta is hospitalized and falls into a coma, even though doctors say that the kind of injury he suffered should not have done that to him. For the duration of his coma, Junk cannot be switched on. Yuta has a dream where he discovers that he never had amnesia; he never had memories prior to waking up in Rikka's house because he was part of Gridman all along, and that the real Yuta was lying dormant. The Neon Genesis Junior High Students manage to repair Junk after realizing this connection as well and Yuta is finally able to wake up. Seeing Utsumi, Gridman takes over Yuta and tells him he has something only he can do, before running back to the Junk Shop to transform and assist Gridknight against a horde of monsters.
He regroups with Anti in the junk shop and tells him to deal with Akane, who had been turned into a kaiju, while he looks for Rikka and Utsumi. Bringing them back to the Junk Shop, he does one last Access Flash along with Anti and the Neon Genesis Junior High Students, bringing back Gridman's true form. The Gridman Alliance manage to heal Akane's heart while Gridman fired the Grid Fixer Beam at Alexis, who had soon been finished off.
Gridman left Yuta after saying goodbye to Rikka and Utsumi, which causes the real Yuta to wake up in the Junk Shop just as the first snowflakes fall, and his parents come back home from their business trip.
- Height: 160 cm
- Weight: 52 kg
- Age: 15 years
- Date of Birth: 8 January, 2003
- Blood Type: AB
In his first transformation, Yuta is forcefully swallowed by Junk and within cyberspace, he connects with Gridman in a similar way to his predecessor, Naoto Sho did in Denkou Choujin Gridman. Gridman then appears in a flash of light.
After Gridman is optimized, Yuta is given the Primal Acceptor (プライマルアクセプター Puraimaru Akuseputā) to properly transform. He says the phrase "Access Flash (アクセス・フラッシュ Akusesu Furasshu)" and enters the computer where he combines with Gridman, giving the Hyper Agent a physical form to fight with.
The Primal Acceptor evolves into its true form and is worn by Yuta, the Neon Genesis Junior High Students, and Anti. They perform the Access Flash together and after that, the Access Code "GRIDMAN" is typed into the popup box on Junk, which then displays the text "Special Signature to Save a Soul". Gridman's true form then bursts forth from within his Primal Fighter form and appears.
- Telepathic Link: Yuta possesses some connection with Gridman, being able to hear his voice some distance away, and is the only one who can see and hear him on Junk's computer screen. Their link is also the reason why they can merge with each other. When he senses a monster, he gets an electric shock on his left hand where his Primal Acceptor is. After Junk is optimized, however, everyone could see and hear Gridman at any time. It is later revealed that this link exists because he is a part of Gridman.
- Mediumship: Compared to normal humans, Yuta has the ability to see Gridman in his computer and the Illusion Monsters. This is eventually expanded to the rest of the Gridman Alliance after Junk had been optimized.
- Primal Acceptor (プライマルアクセプター Puraimaru Akuseputā): A device given to him by Gridman. It is worn on his left wrist and is concealed under the red band he wears when he goes out in public.
- Access Flash (アクセス・フラッシュ Akusesu Furasshu): His mode of transformation into Gridman, Yuta goes over to Junk and says this phrase to unite with the Hyper Agent.
- G-Call (Gコール G Kōru): The Primal Acceptor flashes when a kaiju is around, warning Yuta of their presence. The only time it failed was against Gonglee, due to its concealment fog.
- As with Akane and Alexis・Kerib, Yuta is in fact a reused concept from the scrapped plans of Denkou Choujin Gridman F. SSSS.GRIDMAN adopted many of these leftover plans. Had the show went on, Yuta was supposed to be one of Ippei Baba's new classmates while he bonded to a different Gridman.
- His status as an amnesiac human host of a modernized titular hero from a pre-2000 Tokusatsu series is shared with Jin from Ultraseven X.
- Yuta's color scheme is based on the Transformers Classics incarnation of Cliffjumper, who travelled from his universe to the Shattered Glass universe. Yuta's red-colored hairstyle resembles the Autobot's horned helmet and his sneakers resemble Cliffjumper's feet and alternate mode.
- Yuta and Cliffjumper are in similar situations, as both find themselves to be strangers in an environment they are supposed to be familiar with.
- The design of his backpack resembles the Barrier Shield component of the original Gridman Sword and Cliffjumper's Wave Crusher.
- The Primal Acceptor was designed by Akira Amemiya, the director of the series.
- According to the voice drama episodes:
- Yuta went over to Rikka's house, tried to tell her something she forgot about, and then passed out. When he woke up, he became an amnesiac.
- Rikka first talked to Yuta when she skipped a ball game and went back to class and saw him alone.
- Hass, Namiko and Rikka acknowledge how red his hair is.
- Yuta is curious about how Hass looks under her mask, which both Hass and Namiko find gross.
- Yuta nervously states that he would go out with Rikka if he had the chance.