Hiro discovered that he can manipulate the time/space continum. Hiro set out to "save the cheerleader, save the world." His abilities have taken him to all parts of the world meeting new friends and making new enemies.
Season 1
Hiro was an office worker at his father's company, Yamagato Industries, in Japan, until one day he accidentally teleported to the future. Here he saw that on November fifth, a bomb would blow up New York. He then returned back to October second. He with his friend Ando traveled to the United States.
There they went to Las Vegas following Hiro's comic from the future created by the precognitive Issac Mendez. After being beat up for cheating and dumped near a desert diner in the outskirts of Las Vegas, a fight ensues, and Ando and Hiro split ways. Hiro meets "flying man" Nathan Petrelli at the diner. Nathan gives him a ride back to Las Vegas, in a car. This entire time Hiro tries to warn "Mr. Issac" that in five weeks he will be dead, as seen when he went to the future. One call, Peter Petrelli picks up and tells Hiro the message, "Save the Cheerleader, Save the World."
Reunited, Ando and Hiro go to the Burnt Toast Diner to wait for further instructions from Peter. Here Hiro meets Charlie who is killed by Sylar. To save her, Hiro goes back in time, but all for naught. Returning to the present, Hiro thinking his quest to save the cheerleader has failed meets Issac. Issac paints Hiro battling a dinosaur, so Hiro vows to get the sword. Taking the painting as collateral, Hiro travels to trade the Linderman group, an avid collector of Issac's paintings for the sword. Hiro's father attempts to stop Hiro, ripping the painting, but is soon persuaded to let Hiro go about his quest. Hiro reaches the sword and trying to escape teleports to the future, where he is captured by Future Matt Parkman.
Future Hiro, Ando, and Future Peter save Hiro at the cost of Future Hiro's life. Hiro and Ando return to the Present and confront Sylar. Sylar breaks the sword and Hiro and Ando get it repaired. While Hiro trained with his Dad, Ando assuming Hiro would give up his quest, tries to confront Sylar again. Hiro saves Ando and returns him to Yamagato industries. Hiro then proceeds to confront Sylar at Kirby plaza stabing Sylar in the chest. Sylar flings Hiro at a building as a last effort and Hiro teleports finding himself in Kyoto, Japan in the year 1671.
Season 2
Hiro is in Kyoto, Japan in the year 1671. He sees the occurance of an eclipse and then is faced by arrows raining down upon him and another man under a symbol on a flag that matches Takezo Kensai's sword. Hiro freezes time to save his hero from an untimely fate only to discover that it was a replacement sent there by the real Takezo Kensai, an englishman dressed as a samurai who had planned on using the decoy as a distraction to snipe his enemies from a tree with a crossbow. Yaeko, the one foretold to be Kensai's princess, is a swordsmith's daughter that repeals her father's payment of his sword. She then goes off to face the bandits herself. Wanting to fix the mistake of altering the past, Hiro donnes his heroe's armor and confronts the bandits in an effort to save Yaeko. Hiro then chases off the bandits by using his powers to collect all their weapons in the blink of an eye. Hiro had saved Yaeko and Kensai's reputation, and had sparked Yaeko's love for Kensei.
Hiro then returns to Kensei and sways him to be the Hero the ledgends had been written about. However, as the two leave Kensei is shot with arrows and killed. When Hiro removes the arromws Kensei shows his unknown ability to heal and regenerates to life. Hiro decided to test Kensei to see if he had truely become the hero of ledgend and forces him to fight 90 ronin to retrieve the "fire scroll". Succeeding, Kensei decides to become the hero that Hiro sees him to be. To this, Hiro decides to leave but falling in love with Yaeko himself and the desire to make sure the timeline is secured, makes Hiro stay.
The Trio of Kensei, Hiro, and Yaeko travel to the dreaded White Beard's camp to save Yaeko's father. However, once Yaeko is save Hiro, weakened by his love, Admits to loving Yaeko and the two kiss much to the pain of the secretly onlooking Kensei. Kensei grows angry and joins White Beard and captures Hiro, Yaeko, and her father.
Hiro, captured in White Beard's camp and drugged on opium to prevent him from using his powers, is freed by Yaeko who had freed herself from her own bindings. Hiro is able to focus long enough to free Yaeko and her father. That night Hiro goes preform the next to last trial of Kensei, to save all of Japan, destroying White Beard's guns. Hiro goes to light the gunpowder cache, but is stopped by Kensei. During the battle Hiro tries to persuade Kensei to change ways and be the hero he was supposed to be. However, Kensei vows that as long as he lives he will destroy everything he holds dear. During the battle, a lamp is knocked over and before it explodes Hiro teleports away.
Hiro returns to Yaeko. Hiro is upset and tells the end of Kensei's story to her. She then tells Hiro that as long as she lives she'll tell the story of the real Takezo Kensei, Hiro. So,, like Kensei, Hiro "cuts out his heart", and returns to his time.
Back in his own time, Hiro discovers his father has been killed. Hiro attempts to save his father but is persuaded that he cannot play god with his powers and must let his father die. Hiro, however, uses his ability to discover his father's murderer, only to discover that it was Kensei.
Hiro begins his quest to stop Kensei. Discovering Kensei's real name, Adam Monroe, Hiro travels back to 1977, where he sees his father imprison Adam for almost releasing a deadly virus. Hiro learns that this virus will be contained in the Primatech facility in Odessa, Texas. Hiro goes to the facility via teleportation and stops time. He searches for Adam only to find Peter Petrelli. Hiro explains to Peter why he is here and what Adam plans to do, but Peter is blinded by the fact that Adam healed his brother after Peter exploded. The two battle but Hiro is knocked out.
Hiro is awoken and joined by Nathan Petrelli and Matt Parkman who are also trying to stop the releasment of the virus. Hiro teleports to Adam and Hiro tells him that he should not of let him live long ago. Grabbing Adam's arm the two disappear. Hiro puts his once hero, Adam Monroe in a casket and buries it in a Japanese graveyard.Hiro later tells Ando that Adam will not hurt anyone ever again.
Season 3
In season 3, Hiro owns 50% of Yamagato Industries and he tells Ando that he is not interested in money and he wants adventure. Hiro claims that it's not his destiny to be in the company. Shortly after that conversation, the family lawyer gives Hiro a document, inside it was a tape and it told Hiro to play it. Hiro plays it and in the tape was his father, Kaito Nakamura. Kaito tells Hiro that there is a family secret insde a safe and Kaito told Hiro to keep it in the safe and never take it out. Kaito tells Hiro that it is his destiny. After watching the tape, Hiro is not happy, he says that he doesn't want to be a sentinel and protect the secret. Hiro then finds a button and it opens up the safe, Hiro thinks that whatever's in that safe, it's his and Ando's destiny.
Inside the safe was a note saying "Press play". When Hiro pressed play, Kaito was on it and was angry at Hiro. He then tells him that inside that safe is a very important formula and that if it falls into the wrong hands, it could destroy the world. Kaito tells Hiro to do whatever it takes to protect it. Just when Hiro takes the formula out, a super fast thing whooshes its way and takes the formula. Hiro quickly stops time but the person was so fast that she could even move when Hiro stops time. She knocks Hiro out and runs off at super-speed. Later that night, Hiro teleports into the future to see what happens if he doesn't get the formula back, in the future he sees Ando killing the future him with some sort of red electricity ability. After seeing that the whole world splits up, after seeing that future, Hiro is detemined to get the formula back. Hiro then hires private detectives to trace down the theif, the theif was revealed to be Daphne Millbrook. Hiro and Ando teleports to her apartment in Paris and they find a lot of stolen goods but not the formula. Hiro reveals to Ando what he saw in the future and Hiro starts to get a bit paranoid around Ando. Hiro comes up with a plan to get the formula back but it failed. Hiro reveals to Ando that he has put a tracking device on Daphne, Ando asks why didnt he tell him and Hiro tells him that he doesn't trust him. Ando then starts to get a bit annoyed.
The tracking device tells Hiro and Ando that Daphne is in Berlin, Hiro finds Daphne and asks her why she's here, she tells Hiro that the other half of the formula will be exchanged and she's waiting to intercept. Hiro tells her that the world would end if he doesn't have the formula back but Daphne tells him that she's only doing it for the money. Daphne tries to run but she couldn't run at superspeed, Hiro then tries to teleport but he couldn't do it as well. Hiro then recognises the Haitian and he realises that his abilities' blocked by him. Hiro then tries to get the formula without his ability but fails, Daphne grabs the other half and he and Ando gets captured by the Company.
Angela then tells Hiro that he has the key to stop the person manipulating them. Hiro and Ando then digs up Adam Monroe believing that he knows who is manipulating them but they shortly loses Adam when he gets captured by the Pinehearst company. Hiro thinks that he needs to be a "Badass" and he joins the Pinehearst company. Knox tells Hiro to kill Ando to proof he's a badass and he uses a fake sword and fake blood to do that. Both Daphne and Knox believes that Hiro has killed Ando and Knox lets him join Pinehearst. Hiro was given his first assignment by Daphne, the assignment was to recruit a future painting man in Africa. Daphne warns him to be careful and Hiro ignores the warnings. Hiro goes to Africa and searches for "Mr. Africa Issac" Hiro tries using his powers but he fails both times. When Hiro doesn't use his powers the future painting bushman tells him that it was all a test and that he is ready to take him to the villains he seeks.
Ando persuades Hiro to go back in time so that he knows how to stop the villains but Hiro refuses fearing that he might create another villain like Adam Monroe. Usutu then tells Hiro that he must choose his own path or have it chosen for him. Usutu then gives Hiro some paste telling him that it is a ancient family recipe. Hiro eats it and shortly afterwards, his eyes turn white and he falls unconcious but his white eyes was kept open. While Hiro was unconcious, he see's into the past and finds out what Arthur Petrelli had done in the past and that he was still alive, he also finds out that one of the villians, Flint, is related to Claires biological mom Meredith. Hiro wakes up and wants to warn the Petrelli's and Meredith but before he can he hears a scream, him and Ando search and find out that Usutu's been decapitated, suddenly Arthur apears and grabs Hiro's head and Hiro starts screaming. Ando tries to attack Arthur but is telekineticly thrown aside, Arthur then gets distracted by a painting of an eclipse and takes his hands off Hiro to look at it. While he's distracted Arthur tells Hiro to teleport, although Hiro doesn't understand he eventually teleport when he see's Arthur coming back. They end up in a bowling alley in Tokyo, Hiro gets happy because they serve waffles, after talking to Hiro, Ando finds out that Arthur erased Hiro's memory and now Hiro's believes he's 10. Ando tries to convince Hiro that he's an adult and has superpowers, at first he's skeptical but Hiro soon believes after he starts using his powers to prank people. After Hiro gets the hang of his powers Ando tells him they need to teleport somewhere to help his memory, Hiro then teleports to a comic book store, which he calls the source of all knowledge. After looking through a couple of marvel books and be shocked at some of marvels current events, Hiro see's a issue of 9th Wonder with him on the cover, Hiro see's the comic which, shows Hiro and Ando reading that comic, Hiro is still skeptical but Ando convinces him. They then go to the end of the comic to see what happens, but all thats there is the eclipes that says "it coming".
Hiro and Ando then travel to Matt's apartment according to 9th Wonders, there, they find Daphne and Ando tells Matt that she can't be trusted, later, Daphne feels guilty and runs back to her old home. Ando then tells Matt that Hiro has lost his memory and needs him to help him regain it. Hiro then continues to behave like a 10 year old and Matt tells him that he is also looking for Hiro, Matt tells him all about the catalyst and what Arthur has been doing and Matt tells them that they can't save the world without Daphne so Hiro teleports Ando and Matt to a corn field and just when they teleported there, the eclipse started to form and Hiro and Matt loses their abilities. Matt tries to get into Daphne's house but couldn't without his ability. After the failure, they return to the corn field and tries to figure out what's happening. Hiro then starts throwing corn at Matt and tells him not to rely to much on his ability and trust in himself . Hiro and Ando then leaves Matt to continue persuade Daphne. Hiro and Ando continue to find out what to do but they realized that they reached the end of the comic. Hiro and Ando travels to a comic book store and asks for the newest issue of 9th Wonders.
Upon entering the comic shop, Hiro is met by two ninth wonders fans, the comic shop owners. Hiro begins to flip through comics but when told that "this isys all the ninth wonders and begins reading of his adventures. After an unknown amount of time, Hiro runs to another room claiming he never wants to grow up. On investigation this revelation is from reading everything he has done in the past few seasons, such as stabbing Sylar, attacking Adam Monroe, and his fathers death. The shop owner after a very Hiro-like speech of ones responsibilities and such, Hiro leaves the room. This is when the other store owner brings up the fact that Hiro and Claire have only been in one panel together, Kirby Plaza, but that "doesn't count because they shared no dialogue." However the second employee points out he found Claire and Hiro watching in the background as Hiro's father gives Noah Claire. Deducing that doing this would restore Hiro's memory, Hiro goes to Claire.
Hiro arrives just in time as Sylar is about to kill Noah in the Bennet house. He then teleports Sylar away as he calls him "bad man". THis is then followed by Hiro reappearing and making Elle disappear. Once this is done, He once agian appears and says "Save the Cheerleader..." and teleports through space and time with Claire. In the past Claire and Hio watch as Claire is given to Mr. Bennet. When Mr. Bennet leaves Claire follows while Hiro watches his mom. His mom he discovers has the ability to heal and when he is alone he goes to her and laments that he has lost his memory and that he needs to be healed. His mother does so and Hiro has a moment with his mother. He then asks for a "light" that was mentioned between his mother and father earlier which must be the catalyst. After giving Hiro the catalyst, his mother promptly dies. That night Hiro meets Claire and he tells her that he has gained the catalyist and they can go. Before they get to though, Arthur Petrelli appears and takes Hiro's power and the catalyst and tosses him off the building. He teleports Claire to the future telling her that she should tell Angela she loses. Arthur then returns to the future himself. A yell is heard then and it is Hiro, hanging from a flagpole calling for help. In the present during this Daphne, Matt, and Ando recover Issac Mendez's sketchbook telling of the last ninth wonders tale. In it it tells of Hiro's venture into the past and his perdicament of being stranded in time. It is decided among the group that if the catalyst worked, a new time traveler could appear to help Hiro and Ando claims that it should be him.
