Hiro Hamada

"We didn't set out to be superheroes. But sometimes life doesn't go the way you planned. The good thing is, my brother wanted to help a lot of people and that's what we're going to do."

- Hiro Hamada

Hiro Hamada is the main protagonist from Disney's 2014 animated feature film Big Hero 6. He is the founder and leader of Big Hero 6, a team of young superheroes whose goal is to protect the city of San Fransokyo. He is based on Hiro Takachiho from the Marvel comic of the same name.

He is voiced by Ryan Potter.

Official Disney bio

 * Robotics prodigy Hiro Hamada has the mind of a genius—and the heart of a 14-year old: his state-of-the-art battle-bots dominate the underground bot fights held in the dark corners of San Fransokyo. Fortunately, big brother Tadashi redirects Hiro's brilliance, inspiring him to put his brain to the test in a quest to gain admission to the San Fransokyo Institute of Technology. When a tragic event changes everything, Hiro turns to a robot named Baymax, and they form an unbreakable bond—and two-sixths of a band of high-tech heroes on a very important mission.

Personality
Hiro Hamada is a young boy with intelligence far beyond his years. Because of this, he can be rather brazen and cocky (especially when he was seen to be bored on during his bot fight with Mr. Yama), but never to the point of arrogance. He spends much of his time using his technology to win money through illegal bot fights (although he claims that bot-fighting isn't illegal, but betting on it is. Regardless, he still does it illegally), something he prides himself on, though his older brother Tadashi heavily disapproves. Whilst Tadashi feels his brother has a greater purpose and should attend college, Hiro believes he holds the knowledge of all that there is to know in the world, showing a strong sense of pride.

Despite his bold nature, Hiro has a much softer side to him, as he's shown to be rather shy in front of crowds and during the process of making new friends, as well as awkward at times. Even so, his compassion is mostly seen when dealing with his older brother Tadashi who, despite his brotherly nagging, holds a special place in Hiro's heart as the latter's best friend and inspiration. When with Tadashi, Hiro's true colors are shown; showing him to be free-spirited, innocently sassy, warm and ultimately very loving and appreciative. Such aspects wouldn't be seen again until the void left by Tadashi's demise is eventually filled by the lovable Baymax, who cares for Hiro in the same sense, forming a strong companionship.

However, underneath his kind heart lies a darker core. At certain points during the movie, the boy genius would allow his anger to cloud his better judgement and commit acts normally out of the question. He is similar to Yokai (the villainous mastermind responsible for the death of Tadashi) in this respect, as both experienced the loss of a loved one, thus mutilating their hearts to the point where they sought revenge against the wrongdoers responsible, going as far as conscious murder. However, what separates the two and ultimately classifies Hiro as a hero and Yokai as a villain is the fact that, unlike Yokai, Hiro not only learns the error of his ways, but he makes a serious effort to right the wrongs he's caused as quickly as possible. Such revelations are mostly due to the comforting nature of Baymax, the legacy of Tadashi and the support of his closest friends, resulting in a newly-reformed young prodigy, who values the lives of all human beings and refuses to carry out acts of justice through the use of violence and murder.

As time would move on following the events of Tadashi's death, Hiro would slowly shape into a heroic, wise and inspirational leader, following in his brother's footsteps. Such traits passed down include Tadashi's philosophy of "looking for a new angle", as well as the devotion to do whatever necessary to help others and make the world a better place for all, especially the innocent and deserving. As mentioned above, Hiro would notably organize the Big Hero 6 team, vowing to protect the city of San Fransokyo in order to fulfill Tadashi's lifelong dream of helping others.

Physical appearance
Hiro is a 14-year old boy. According to official sources, he is 5'0" in height and rather slender. He can often be found in a blue hoodie jacket, a red shirt with a robot on it, long dark beige shorts and dark brown trainers with yellow laces. He is fair in skin and has brown eyes and messy black hair. His eyelashes and eyebrows are somewhat thick and his eyes are a rounded almond shape. When he smiles or opens his mouth, a gap in his teeth can be noticed along with a slight overbite.

Hiro's super-suit is made of primarily indigo with red accents and black armor, with black clothing underneath that covers most of his body up to his knees, along with steel-toe black sneakers. On his suit are red magnetic pads, used to carry onto Baymax's armor for transportation and battle purposes.

Powers and Abilities
Unlike the rest of the team, Hiro's armor lacks any real ability, as his true power lies within his genius. As mentioned above, however, his suit enables him to hold onto Baymax with magnetic pads whenever the robot takes flight with him aboard, as well as partial protection from destruction. His helmet is also equipped with a communication device, enabling him contact with the rest of the team members despite their distance, if any.

With his vast intelligence, Hiro has the power to create various new concepts and inventions, often varying in scale, from a small yet powerful battle bot to a state-of-the-art super suit. Not only was he able to "upgrade" both himself into a crime-fighting vigilante, but also Baymax as well as his four closest friends, creating a series of powerful battle suits with various powers and abilities; making them a force in their own rights.

Other inventions notably created by Hiro include the Microbots (which were primarily used throughout the film as Yokai's source of power), Baymax's original battle suit (which was equipped with karate action), programming chips capable of enhancing (for better or worse) the knowledge and personality of a robot and Baymax himself, whom the boy genius was able to recreate in every little detail at the end of the film.

Role in the film
Hiro Hamada is a young prodigy living in the high-tech city of San Fransokyo along with his aunt Cass and older brother Tadashi, who wants Hiro to become a productive member of society.

Despite his high intelligence, Hiro spends his time participating in underground bot fights throughout the city, which has frequently led to Tadashi having to bail him out of tough situations. On one particular night, Hiro takes part in an illegal bot fight against champion Mr. Yama and leaves the battle victorious. Out of spite, Yama and his goons attack the boy, who is immediately rescued by Tadashi. Though they escape Yama and his thugs, the two brothers, along with everyone else involved in the illegal bot fights, are caught by the police and arrested. Hiro and Tadashi are released that same night on account of Cass, who takes them home, scolding them along the way. The two are able to bypass punishment, but a frustrated Tadashi scolds Hiro on his bot-fighting obsession, wanting him to put his intelligence to better use.

Hiro scoffs at the idea and makes an attempt to join another bot fight. Tadashi offers a ride, but instead takes his brother to his school, the San Fransokyo Institute of Technology. There, Hiro meets Tadashi's friends--Honey Lemon (a hyperactive chemistry genius), GoGo Tomago (a sassy adrenaline junkie), Wasabi (a neurotic neat freak) and Fred (a hopeless fanboy with a love of comics and Japanese Kaiju). Though Hiro is shy and quiet throughout the introductions, he's secretly amazed by the institute, finding the inventions breathtaking, though he doesn't admit so just yet. After meeting the team, Tadashi takes Hiro to his lab, where he introduces him to Baymax (a squishy white robot, programmed to be a personal healthcare companion and created as a means to heal the sick and injured). Tadashi explains Baymax was a creation meant to help people around the world and is additionally explained to be programmed by a special healthcare chip which, according to him, makes Baymax who he is. After the introduction, the two run into Professor Callaghan, a world-renowned robotics expert, mentor of Tadashi and Hiro's personal idol. With the help of Tadashi, Callaghan cunningly convinces Hiro to enroll in the Institute, claiming the school is a place where the boundaries of robotics are pushed and geniuses put their brains to the test in order to shape the future. Callaghan's words instantly strike Hiro and after departing the school, he confesses his burning desire to join the Institute.

According to Tadashi, the school holds an annual convention, where up and coming geniuses are meant to showcase new creations. Those who impress Callaghan are accepted into the school. Tadashi advises Hiro to concoct a creation to do just that, but the boy-genius instantly hits a block of thought and nearly gives up. Tadashi restores his brother's faith by assisting him in enhancing his thought process, eventually leading to Hiro's breakthrough. After a long period of work and planning, with the help of Tadashi, GoGo, Wasabi, Honey and Fred, Hiro creates the Microbots--miniature robots capable of forming anything that comes to mind through the use of a telepathic headband transmitter. Hiro takes his inventions and showcases them at the convention. Though nervous at first, Tadashi eases his little brother, resulting in a fantastic showcase that thoroughly impresses both Callaghan and famous tech-guru Alistair Krei. Krei offers Hiro vast wealth in exchange for ownership over the Microbots. Callaghan interferes with the offer by accusing Krei of using technology and science for selfish reasons, advising Hiro to deny the offer. A frustrated Krei leaves the scene while Callaghan congratulates Hiro on his success by granting him admission into the school. In celebration, Cass offers to take Hiro, Tadashi and their friends back to the cafe for a free dinner, though Tadashi and Hiro separate to have some alone time.

Once they're alone, Tadashi congratulates his younger brother on his success, proud to see him use his genius for bigger things in life. Suddenly, however, the school's fire alarm goes off, prompting Tadashi and Hiro to rush to the chaos. There, they see civilians escaping. One woman informs the boys that Callaghan is still inside the burning building and Tadashi decides to go in after him. Hiro tries to stop him, but Tadashi goes forth, not willing to risk losing Callaghan. Hiro then attempts to follow behind, but before he's able to, the building violently explodes, rendering him unconscious and killing both Tadashi and presumably Callaghan. A funeral and memorial are held, and Hiro falls into deep depression at the loss of his brother and best friend. Cass tries to comfort her nephew, but to no real avail. As such, Hiro remains alone in his room, ignoring both Cass' attempts to cheer him up and his equally-saddened friends.

One day, Hiro accidentally stubs his toe and his pain summons Baymax, who was originally thought to be out of commission.

Baymax explains he heard the sound of distress and offers assistance. Hiro denies his offer, and tries to deactivate the bot, only to accidentally stumble upon one of his Microbots, which is still active and trying to reunite with the other bots. Hiro, thinking that the rest of his Microbots and the transmitter were destroyed in the fire, ignores the bot's activity, believing it to be malfunctioning. Baymax, however, takes notice of this and acknowledges it, only to have Hiro sarcastically order Baymax to find out where the bot is trying to head, which the robot takes literally and does just that. Hiro chases after a wandering Baymax through the city and the two eventually find themselves at an abandoned warehouse. The two break in and they soon stumble upon a machine creating millions of Microbots. As Hiro ponders on the mysterious discovery, the Microbots rise and attack. Hiro and Baymax evade them hastily and eventually encounter a dark, masked figure named Yokai; the man responsible for the theft of the Microbots. The masked man pursues the duo, but they eventually escape at the last minute, immediately heading to the police station to report the attack.

The two give their claims to Officer Gerson, who finds their story to be rubbish, thus denying them lawful assistance. Just then, Baymax begins to lose battery, forcing Hiro to leave the station and return home to have the robot charge. After sneaking past an oblivious Aunt Cass, Baymax begins to charge and Hiro takes a breather from the exhausting day. Just then, Baymax acknowledges Tadashi's disappearance, asking for his whereabouts. Hiro reveals Tadashi's unfortunate demise, but the mention of the fire being an accident sparks an epiphany. After the encounter with Yokai, Hiro realizes that the fire was no accident and recruits Baymax into helping him take down the masked culprit, wanting to avenge his brother's death. As such, Baymax is given a few upgrades, including a super-suit equipped with karate-like battle programming and a new programming chip, which gives him such abilities. After his new upgrades are put to the test, the two head out to find and capture Yokai. They arrive at the warehouse, only to find it vacant. However, using the last Microbot to track him, Hiro and Baymax are led to the docks, where they find the demonic Yokai emerging from the fog with a massive piece of technology. The two go into silent hiding until Honey, GoGo, Wasabi and Fred arrive, having followed the two there after spotting them snooping about the city alone.

Hiro advises them to leave, until the group is attacked by Yokai. Baymax tries to battle the masked villain, only to be thrown onto the top of Wasabi's van. The gang retreats from the scene with Yokai immediately following behind them, leading into a chase throughout the city. As they try to escape, Yokai makes several attempts to kill the team, but luckily, with GoGo's reckless driving, they manage to escape by driving off a ledge and into the ocean, having Yokai believe them to be dead, thus vanishing once again. Baymax manages to rescue the team and bring them back to shore and, to recover, the group heads to Fred's mansion home. There, they ponder on the true identity of Yokai and how to find him before Baymax reveals that he scanned the masked man's body, allowing them to track him down via body temperatures and other health-related attributes. Before the mission to bring Yokai to justice begins (with the objective being to remove his mask to eliminate his power), Hiro decides to upgrade both himself and the rest of the team, believing they'd have a much better chance if they all join together as superheroes.

After some scientific modifications and training, the group of friends become the team Big Hero 6, bent on taking down Yokai. To do so, the team believes his mask is his source of power and the objective is to retrieve the mask to cease his control over the bots. Baymax is the last to be upgraded and after his new super-suit is revealed, he and Hiro take a test flight for the first time throughout the city, eventually landing on one of the air balloons towering over the city and overlooking a sunset. Hiro and Baymax take the time to relax and bond for a short moment, which brings happiness to the boy. Realizing this, Baymax asks Hiro if he's satisfied with his care, as his true objective throughout their adventure is to ensure Hiro's happiness and satisfaction, claiming Hiro to be his patient. Hiro denies Baymax's question and returns to the matter at hand.

After scanning the city to find a match to Yokai's health information, Baymax discovers a match on an island not far from the city. The team heads to the area, which is revealed to be an abandoned facility. There, they find a machine in the process of restoration, but are unable to uncover what it is exactly. However, they soon find a room with recordings taking place in the facility.

After watching, they learn that the facility originally belonged to Alistar Krei and the machine was a portal meant to enhance transportation. The test subject, a woman named Abigail, was the first to try it out, but as she did, the machine malfunctioned. Instead of calling off the procedure, Krei insisted that they move forward, resulting in a tragic accident that left Abigail lost in the portal and apparently killed by the machine's destruction. The incident results in the closure of Krei's facility and the team then comes to the conclusion that Krei is responsible for stealing the Microbots in hopes of rebuilding his portals. Just then, Yokai returns and attacks once more. A battle follows and in the process, Hiro attacks Yokai, causing the two to topple down a flight of stairs, which knocks off the villain's kabuki mask. Yokai's true identity is then revealed to be Professor Callaghan. Callaghan confesses his crime of stealing the Microbots and reveals that he used them to escape the fire alive and unharmed. A heartbroken Hiro reveals that Tadashi died trying to save him, but Callaghan doesn't care, blaming Tadashi for his own death. Furious, Hiro orders Baymax to kill Callaghan. Baymax denies such an action, explaining he's unable to bring harm to a human being. Hiro, blinded by hatred and grief, removes the robot's healthcare chip, leaving only his programming of battle and destruction, sending him on a violent, mindless rampage in an attempt to kill the professor. Seeing this, GoGo, Fred and Wasabi try to fend off the bot as Callaghan manages to escape.

Eventually, Honey recovers Baymax's healthcare chip and restores the robot to his original peaceful settings. Realizing what he's done, Baymax apologizes to the team for causing harm, but Hiro berates them, blaming them for Callaghan's escape. The team retorts by explaining that the plan was never to kill Callaghan, but instead, to merely apprehend him. Leaving the team on the island out of anger, Hiro and Baymax return home to recover Baymax's suit. Baymax talks to Hiro about the situation of killing Callaghan, asking if his death would appease the boy. Instead of answering, with his mind clouded by thoughts of fury, revenge, sadness and the loss of Tadashi, Hiro breaks down in tears. Baymax comforts him by showing him videos of Tadashi, which he recorded during his creation process. Tadashi's presence and loving words bring enlightenment to Hiro, who thanks Baymax for his comfort. Honey, GoGo, Fred and Wasabi soon arrive as well. Instead of being upset with Hiro, they, too, comfort the boy, understanding that his actions were only out of grief and vows to bring Callaghan to justice. Before they set out, the team shows Hiro a recording they found, which reveals that Abigail was the daughter of Callaghan and the entire goal behind his villainy is to extract revenge on Alistar Krei.

The next day, Alister Krei is in the middle of an important showcase, just as Yokai arrives and captures him. Yokai reveals himself to be Callaghan and the villainous professor reveals his plot to use the newly-recreated portal to destroy both Krei's new building and Krei himself. Alistar tries to talk sense into the villain, explaining the incident with Abigail was an accident, but Callaghan ignores him and proceeds with his plot. Just then, Hiro and the team arrives. Callaghan commands them to stand down, but Hiro tries to sympathize with the professor, explaining the fact that extracting revenge isn't the way to handle his daughter's death, but Callaghan's fury gets the better of him and his plans to kill Krei and destroy everything he's ever built proceeds. Hiro and the others battle the villain, but Callaghan soon gets the upper hand and leaves the team members to die as his plot is set in motion. Fortunately, Hiro uses words of wisdom from Tadashi to successfully guide each member of the team to safety. Hiro then concocts a new plan, instructing the team members to somehow send the Microbots into the portal to eliminate Callaghan's source of power, whilst he and Baymax take on Callaghan himself. The plan is set in motion and Callaghan eventually loses control over the Microbots while the portal itself is soon subdued.

With his plans foiled and power stripped, the team apprehends Callaghan, but Baymax senses life within the portal, though the being is said to be in hypersleep. Baymax and Hiro realize that it's Abigail and the two journey inside to save her. The two soon find Abigail, asleep in her capsule, and as they make their escape, some of the debris from the destruction of Krei Tech strikes them, causing Baymax to lose most of his armor. The two manage to recover quickly and proceed with their escape, only to find that the portal is soon closing. Baymax decides to use his rocket-fist to send both Hiro and Abigail to safety, but Hiro realizes that this will result in the robot's sacrificial death with Baymax trapped in the portal and denies such a plan, not wanting to lose him. Baymax disregards his own safety to help of Hiro, reassuring his friend that he'll always be with him. Hiro then tearfully hugs Baymax as he bids him farewell, telling the robot that he is satisfied with his care. With these words, Baymax sends Hiro and Abigail off, leaving himself trapped in the portal and eventually destroyed. Hiro reunites with the others and reveals Baymax's demise. Soon afterwards, the police and paramedics arrive to care for Abigail and arrest Callaghan.

Following these events, Hiro has made a tremendous recovery from his depression as he is shown to spend his days with Honey, GoGo, Wasabi and Fred and finally joins San Fransokyo Tech as an official student. Within Tadashi's old lab, where Hiro has settled, the young genius has stored Baymax's last piece of armor: his rocket fist, reminiscing of their time together fondly as he comes across it. Within the grasp of the fist, however, Hiro finds Baymax's original programming chip (which contains both his personality and memories) that he did not know was there for a very long time after Baymax's presumed death. After some work, Hiro is able to restore the robot, reviving him from his demise and reuniting at long last. The two rejoice in their reunion with a loving embrace and Hiro reassembles the Big Hero 6 team, dedicating themselves to protecting the city from any and all problems, thus finally putting his incredible potential to great use as Tadashi always wanted.

During the credits, newspapers highlight that Hiro has been awarded a grant from the university and the Big Hero 6 team doing heroic deeds in the city. Another newspaper shows a ceremony of a building dedication in Tadashi's name taking place, in which Hiro accepts the honor on behalf of his late brother.

Printed media
Hiro's story, relationships and overall character is further analyzed and developed in several printed stories.

The currently ongoing manga series Baymax, delves into Hiro's past, revealing his upbringing and relationship with Tadashi, prior to the events of the film. It is revealed that Hiro was dubbed a genius at a very young age (being able to solve a problem no one could have) and, as a result, he found himself bullied and beaten by a group of envious kids on occasion, though Tadashi would always come to his rescue, yet he'd lie and say that it wasn't on purpose. As he grew older, Hiro became increasingly antisocial, even growing distant from Tadashi. Nevertheless, the elder sibling made attempts to keep the bond between Hiro and himself strong by crafting fun inventions for them to share, such as a miniature airplane for two. With the latter, Hiro's enthusiastic side saw a resurgence, and together, the brothers spent their days side by side as scientific partners and best friends.

Hiro and Tadashi centers around the relationship shared by the Hamada brothers, where they are shown to share secret rules (at least 457 of them) and continuously joined together to concoct various inventions. It's also revealed that Tadashi supplied his younger brother with a journal, to keep track of his latest endeavors, which would tie into Hiro's Journal. This book focused on the inner thoughts of Hiro during the course of the film, including his excitement to join the ranks of San Fransokyo Tech, his devastation over the loss of Tadashi, and more; all told by written journal entries and photographs.

Video games
Hiro has made numerous appearances in video games and applications, most of which are spin-off adventures of the film, including Big Hero 6: Baymax Blast and Big Hero 6: Bot Fight.

Disney INFINITY 2.0
Hiro and Baymax appear as playable characters in the second installment of the popular game, donning their superhero outfits.

Hiro's main source of power and attacks in the game are his Microbots, which, like in the film, can be used in combat, creating impressive damage to enemies.

Aside from that, Hiro also has the ability to ride atop Baymax, being one of the few characters in the game with the ability to ride on another playable character (the other being Rocket Raccoon from Guardians of the Galaxy).

Hiro can additionally use booster jumps for super-stealth spying purposes.

Big Hero 6: Battle in the Bay
Taking place after the events of the film, San Fransokyo falls under the attack of a battle bot invasion, at the hands of Mr. Yama, who seeks vengeance on Hiro for humiliating him and "usurping" his bot-fighting championship. With this, Hiro and the team band together to defeat the villain.

Disney Parks
From November 2014 to early 2015, Hiro and Baymax appeared as meetable characters to promote the film at The Magic of Disney Animation in Disney's Hollywood Studios and at the Starcade in Disneyland.

Hiro also makes a cameo appearance in the 2014 rendition of World of Color: Winter Dreams alongside Baymax, as well as in the Disneyland Paris show Disney Dreams!.

Tadashi Hamada
Tadashi is Hiro's older brother and was the most important person in Hiro's life, even after his death. Because their parents died when he was at a young age, Hiro has always looked to his older brother for guidance and advice. They were best friends and even had a set of rules they came up with that only they knew (according to the book, Hiro and Tadashi). They've shared a bedroom since they moved into their Aunt Cass's cafe but don't seem to mind and enjoy each other's company. Tadashi has always been there for Hiro whenever he needed him and the two balance each other well, as Hiro is more creative with his inventions while Tadashi is more practical and by the book as shown in Hiro and Tadashi. Tadashi sees the potential in Hiro and feels it is wasted when, after Hiro graduates from high school, he chooses to engage in a career in botfighting rather than continue his education and use his knowledge to improve the lives of others. Because Hiro is cut off from other people and because Tadashi has been with Hiro since the moment he was born and practically raised him, Tadashi understands Hiro the best out of everyone and was even the one to interest Hiro in robotics. He is also more able to persuade Hiro to do things, as shown when he manages to persuade Hiro to apply to San Fransokyo Institute of technology. He is kind and caring towards Hiro, but is also capable of being stern, demonstrated when he lectured Hiro about how he would get into trouble eventually for his bot fighting obsession and wanted him to stop. He was also goofy, as shown when he grabbed Hiro upside down to shake some ideas into his head. Nonetheless, he was encouraging of Hiro's intelligence and pursuit of robotics and was always there to protect him, as shown when he saved Hiro from Mr. Yama and his henchmen.

Tadashi's death had the greatest impact on Hiro, who fell into depression and refused to leave his room or eat after the incident. He also refused to attend the San Fransokyo Institute of Technology, despite his initial excitement to join. The death of his older brother also hardened Hiro's heart, and led him down a path of murderous vengeance, as seen when the boy manipulated Baymax's programming in hopes of killing Yokai, only to be stopped by his own friends.

When he tried to pursue the path of vengeance again, Baymax refused, as the latter knew this would not help Hiro and wouldn't be what Tadashi wanted. Hiro then watches clips of Tadashi building Baymax on the robot's video monitor and realizes Tadashi's goal was to help people and that he should do the same. This inspires Hiro to seek justice rather than revenge on Callaghan, make up with his friends, and continues to do good for the world by becoming a hero.

Cass Hamada
Cass Hamada is Hiro's and Tadashi's aunt. Hiro tends to stress her out and cause her to 'stress eat', due to his illegal bot fighting but she loves him nonetheless and vice versa. She is very supportive and proud of his abilities and was overjoyed when his Microbot exhibition won him an invitation to attend San Fransokyo Institute of Technology. Like Hiro she also mourned the passing of Tadashi. She would bring food to Hiro after Tadashi's death as Hiro fell into a severe depression and wouldn't leave his room. She tried to encourage him to go to college because Tadashi would've wanted it and she wanted him to recover, but he remained silent and she decided to give him space. When Hiro left his room for the first time in weeks and he lied about going to register for classes (he was really going to catch up to Baymax), she was overjoyed and hugged him. Overall, the two have a positive relationship and are close, especially since now they are the only known close relatives each has. However, it is interesting to note that Hiro did not want to tell her about Baymax and that he seems to be keeping his superhero persona a secret from her. This is most likely because she has been shown to worry about Hiro and disapproves of him doing dangerous activities (such as bot fighting) and after Tadashi's death she might forbid him to continue being a superhero as it would put him at risk.

His parents
Hiro's parents died ten years ago when he was only three. While he doesn't know much about them, he seems to be somewhat saddened at the mention of their deaths when Tadashi brings up how disappointed they would be if they knew he was bot-fighting. However, he tries to brush it off by claiming he doesn't really care what they would think of his behavior since they're dead.

Baymax
Their relationship started out basic. Hiro was impressed with Baymax when first introduced, but when they reunited, he was less than thrilled as Baymax served as a reminder of Tadashi's death. However, because Hiro unintentionally summoned Baymax when the former expressed pain, the robot viewed Hiro as his patient, becoming solely devoted to him and unable to dismiss himself until the boy is satisfied with his care, and vocally expresses the fact. This led Baymax to carry out every small order given by Hiro, no matter how literal or sarcastic, in hopes of improving the boy's health, as a result of programming. As time would go on, however, Baymax's treatment towards Hiro began to change. As the robot began learning and understanding the basics of human emotion, a personal bond with Hiro began to form. His dedication towards his "patient" was no longer due to programming, solely, but also because of a mutual love. In turn, Hiro grew to care for Baymax, who served as his ultimate form of comfort, a loving reminder of Tadashi, and a nurturing companion. This is powerfully showcased when the duo found themselves trapped within Yokai's portal while trying to save Abigail. While Baymax was willing to sacrifice himself, Hiro strongly refused, as he didn't have the strength to lose him, too. Nevertheless, he fought through his emotions using Baymax's lesson of overcoming loss, but not forgetting, allowing him to bid farewell to his companion, in addition to expressing his love for the first time through a hug.

Following these events and Baymax's eventual revival, the duo remains as close as ever, forming a brotherly relationship and spending their days beside one another through all events; including their mission to protect the world in Tadashi's honor.

Big Hero 6
Hiro was introduced to the rest of his team, which consists of Fred, GoGo Tomago, Wasabi, and Honey Lemon, when he was tricked by Tadashi into visiting his college. He got to meet each and understand their individual quirks while also being impressed by each of their inventions. He was shy around all of them, as he appears to not open to strangers as easily. However, after he proclaimed his desire to apply to the institute, he immediately began working with them to develop Microbots. By the time of the convention, he had become good friends with everyone. After the death of Tadashi, the team members made the decision to take Hiro under their wings, comforting him, supporting him, and protecting him throughout the film, creating a close bond. This would continue after Baymax's supposed demise near the end of the film, as they helped Hiro overcome yet another loss and happily spent their days with the young boy by their side as the best of friends. Honey and Fred served as enthusiastic supporters of Hiro, Wasabi often watched out for Hiro's health and physical well being, while GoGo is arguably the closest to be the boy, eventually taking the role of a protective, almost parental figure as the course of the film continued.

Yokai/Callaghan
Being a word-renowned scientist and personal mentor of Tadashi, Hiro initially looked up to Professor Callaghan, showing great respect and admiration towards him. Impressed by Hiro's knowledge, Callaghan was able to slyly convince the boy genius to give up botfighting to join the Institute to "challenge himself." It is possible he did this knowing of Hiro's intelligence and wanted him to apply to the school in hopes of stealing one of his inventions (though this is up for debate). Hiro impressed Callaghan at the convention with his Microbots and Callaghan warned him against accepting Krei's offer, manipulating him to say no. When Callaghan was "trapped" in the burning building, Tadashi went in to save him, losing his life in the process. When Hiro discovered Callaghan had started the fire and refused to save Tadashi (showing no concern for Tadashi's life or the fact he tried to save him) Hiro was willing to kill the professor as revenge and was only stopped by his team's intervention. However, after Baymax calms him down, he realized his beloved brother wanted to help people, not hurt them, thus realizing he needed to bring Callaghan to justice without harm.

When Hiro confronted Callaghan once again, he made an attempt to reason with him, as he (having discovered the villain's motivations) understood the pain of loss, and wanted to give the same support his teammates provided him with. However, a bitter Callaghan refused and battled the boy genius, in hopes of killing him. After destroying the Microbts, thus leaving Callaghan powerless, Hiro made the ultimate decision to spare the former professor's life, having set aside his thirst for vengeance in exchange for the moral codes of Tadashi and Baymax. Not only that, he also made the choice to risk his own life to successfully save Callaghan's daughter, after discovering she was still alive within the portal. Though Callaghan showed no forward gratitude towards the hero, he met his defeat through imprisonment, and presumably permanent separation from his only loved one, finally receiving punishment for all the damage he's done, as well as grating Hiro closure. However, Callaghan's expression at the end implies that he shows remorse for what he had done, ultimately realizing that what Hiro said is right; extracting revenge will not make things better.

The emotional core of Big Hero 6 is driven by four key characters, their arcs, and the relationships they share with one another, being Hiro, Tadashi, Baymax, and Callaghan. As such, Callaghan serves as a omen of what Hiro would have become if he allowed his pain to consume him. However, unlike Callaghan, Hiro had friends and family who supported him through the ordeal and reminded him justice, not vengeance, is the answer.

Alistair Krei
The two have a basic relationship and are, at the moment, good acquaintances. Hiro first met Krei at the convention where he was showing off his Microbots and Krei immediately took an interest, hoping to buy the Microbots. However, Callaghan warned Hiro that Krei was known to cut corners and subtly manipulated Hiro to refuse. Krei was clearly disappointed. When Hiro went to an abandoned Krei lab to track down Yokai, he initially grew to believe Krei was Yokai but was proven wrong after taking Yokai's mask and learning it was Callaghan. He also learned that Krei's teleportation experiment resulted in an accident that presumably killed Abigail which eventually turned Callaghan into Yokai. Despite finding this out, Hiro didn't seem to hold a grudge against Krei for indirectly creating Yokai as he tried his best to protect him from the masked villain. This could be because he knew it was an accident or because he wanted to stop Yokai's plan for vengeance. Krei was ecstatic when the Big Hero 6 team came to rescue him and even openly stated his love of Baymax, apparently growing a true liking for the team following these events. When Hiro goes to save Abigail, Krei objects, likely showing concern for the boy's safety. However, Hiro assures him by telling him the same words that Tadashi had told him "Someone has to help". He seems to have learned his lesson and even built a museum in Tadashi's honor, possibly as a way to make amends since he indirectly created Yokai and therefore was linked to Tadashi's death. While the two don't have much interaction, it can be presumed Hiro holds no hard feelings against Krei and Krei is thankful for everything Big Hero 6 has done for him.

Quotes

 * "Hiro. Hiro Hamada."
 * "Can I try? I have a robot. I build it myself."
 * "No more Little Yama."
 * (After Tadashi says that bot-fighting is illegal) "Bot-fighting is not illegal! Betting on bot fights, that's—that's illegal. But, so lucrative!"
 * "You gave me a heart attack!"
 * "What? Go to college like you? So people can tell me stuff I already know?"
 * "Looks like a walking marshmallow." (To Baymax) "No offense."
 * (When Tadashi takes him to his school) "What are we doing at your nerd school!?"
 * "Stop! Stop! Stop! Stop! It's just an expression!"
 * "Uh, hey. B-Baymax, I didn't know you were still... active."
 * "I'm not crying!"
 * "DON'T scan me."
 * "Unbelievable!"
 * "Oh, I just stubbed my toe a little. I'm fine."
 * "A zero? I'm okay, really. Thanks. You can shrink now."
 * "People keep saying he's not really gone, as long as we remember him. But it still hurts."
 * "He was controlling them telepathically, with a neural-cranial transmitter!"
 * "We've gotta catch that guy. But first... You're gonna need some upgrades."
 * "Baymax can handle that guy!"
 * "You wanna keep me healthy don't you?" (Holds up a wooden board) "Punch this." (Baymax splits the board in two) "Yes! Hammer Fist!" (Baymax destroys three boards of wood) "Side Kick!" (Baymax destroys a large wooden structure) "Knife Hand!" (Baymax destroys more wood) "Back Kick!" (More destroyed wood) "GUMMY BEARS!" (Baymax gets a bag of gummy bears from a vending machine) "Yes!"
 * "What do you say, buddy?"
 * "Baymax, destroy."
 * "Does this symbol mean anything to you guys?"
 * (During Baymax's first test-flight) "Thrust! Thrust! Thrust!" (later) "Too much thrust. Too much thrust! TOO! MUCH! THRUST!"
 * "No. No, no, no, I—I just have to look for another angle." (Gets an idea) "Got it! I'll scan the whole city at the same time. I just have to upgrade Baymax's sensor." (Gets another idea) "Actually, if we're gonna catch this guy, I need to upgrade all of you."
 * "No, we can be...way more."
 * "Tadashi's gone!"
 * "No! There's gotta be another way! I'm not gonna leave you here! I'll think of something!"
 * "I'm satisfied with my care."
 * "Which means... what?"
 * "Okay. Let's get you back in your luggage."
 * (To Baymax) "Kick it down!" (later) "Punch it!"
 * (To Baymax, after he says that he is not fast) "Yeah, no kidding!"
 * (To Aunt Cass) "Uh, the thing is..." (runs hand through his hair) "Since I've registered so late, I've got a lot of school stuff to catch up on."
 * (To Aunt Cass, trying to cover up Baymax) "M-Mochi! Ooh, that darn cat!" (looks disapprovingly at Mochi cuddling his legs)
 * "Megabot, Destroy!"
 * "That's kinda the idea, buddy. You look sick!"
 * "I fail to see how you fail to see that it's AWESOME!"
 * "Nothing! No ideas! Useless...Empty...Brain..."
 * "Yeah. I've never seen electro-mag suspension on a bike before."
 * "I got nothing! I'm done! I'm never getting in!"
 * "Whoa! What?!"
 * "Y'ah think?"
 * "That's okay. No touching."
 * "Trust me, (rolls in a swivel chair before exercising fingers) it will be."
 * "I know what you're gonna say." (Immitates Tadashi) "I should be proud of myself 'cause I'm finally using my gift for something important."
 * "Ha, ha, hilarious." (Later) "WHAT?!"
 * (To Tadashi) Hey, I, um, I wouldn't be here if it wasn't for you, so...y-you know, thanks for not giving up on me."
 * (To Baymax after he showed him Tadashi's recordings) "Thank you, Baymax...I'm so sorry...I guess I'm not like my brother."
 * "Tadashi, no!" (Last words to Tadashi before he runs into the building)
 * "We didn't set out to be superheroes. But, sometimes, life doesn't go the way you planned. The good thing is, my brother wanted to help a lot of people. That's what we're gonna do! Who are we?"

Trivia

 * According to Tadashi, Hiro graduated high school at the age of 13.
 * According to Hiro, he lost his parents at the age of 3.
 * He seems to quote Tadashi sometimes, such as 'Unbelievable' and to look at things from a different angle.
 * He is also the original creator of the Microbots; Yokai's primary source of power.
 * Hiro and Baymax's flight through the city is a reference to Iron Man when Tony Stark took his first flight in his first cinematic film.
 * He is the second Disney hero who wanted revenge for his older brother's death, the first being Kenai from Brother Bear.
 * Hiro is also the second Disney hero to have his sibling die during the film, the first being Kenai.
 * Both Kenai and Hiro's movies have the same editor, Tim Mertens.
 * Unlike Kenai, Hiro doesn't have a love interest.
 * He is also similar to Lewis from Meet the Robinsons, as both are orphans who are intelligent and love to invent (though Lewis was initially less successful than Hiro).
 * In the Japanese manga adaptation, it is shown that Hiro showcased high intelligence from a very young age, which caused him to be bullied by others, and needing Tadashi to protect him. This may explain Hiro's antisocial, shy behavior around others along with his cockiness in his own intelligence.
 * It is also shown from the manga that he has been smarter than Tadashi.
 * Counting the manga version of Big Hero 6, Hiro is the third Disney character to be bullied. The first was Lilo, the second Vanellope von Schweetz.
 * The 2013 Rotoscopers video and early information regarding the plot depicted Hiro with a slightly different backstory: He was already attending classes with Tadashi and could not fit in with the other students due to his intelligence (though he doesn't seem to mind). The Rotoscopers video also depicted Hiro as part of a "science club research team" lead by Tadashi (most likely consisting of Honey, GoGo, Wasabi and Fred) in which each individual would make different things and would eventually lead up to a competition. Like Tony Stark, Hiro felt pressure over using his intelligence for good or just building battle robots in the basement (garage in the final film).
 * Also, in early stages of the story, Hiro was responsible for the creation of Baymax, as opposed to Tadashi, just like in the comic book.
 * According to Baymax's first scan, Hiro has a slight allergy to peanuts.
 * Hiro's name, written in Japanese, is "ヒロ". The transliteration of the English word "Hero" in Japanese is ヒーロー (Hīrō).
 * Hiro loves Gummy Bears, and was excited when he asked Baymax to retrieve said item.
 * Hiro, along with his comic counterpart, shares many physical traits with fellow Marvel character Amadeus Cho: both are of Asian descent and bear a slight resemblance to each other along with being child prodigies.
 * Hiro has a Nintendo Entertainment System (NES) controller connected to his computer in his bedroom.
 * He also has a poster of the deleted villain "Mr. Sparkles" in the same area.
 * Hiro is ticklish.
 * Along with Hiro's gap in his front teeth, he has a slight overbite. In addition, in one scene, Hiro was seen sticking his tongue out to bring a straw up to his mouth before sipping, a habit common among people who sucked their thumbs as children. Hiro Hamada.png
 * Hiro's super-suit has comically large fists, which can be attributed as a nod to the Incredible Hulk or Wreck-It Ralph.
 * Hiro also shares similarities with Treasure Planet's protagonist, Jim Hawkins.
 * Both their movies have the same producer, Roy Conli.
 * Both are teenagers.
 * Both have a well developed knowledge of robotics.
 * Both have gotten in trouble with the law on more than one occasion.
 * Both were raised by a single female relative.
 * Neither Hiro nor Jim have love interests.
 * Both have villainous mentors; Robert Callaghan for Hiro, and John Silver for Jim.
 * Both have a robot companion; Baymax for Hiro, and B.E.N. for Jim.