Publication Date: 
8th Nov 2014
Written By: 
Image Work: 
Real name





5' 4" (Hiro);
6’ 5” (Baymax)


110 lbs. (Hiro);
480 lbs (Baymax)


Black (Hiro);
None (Baymax)


Brown (Hiro);
Red (Baymax)

First appearance

Sunfire & Big Hero 6 #1

Known relatives

Tomeo Takachiho
(father, deceased),
Maemi Takachiho (mother)


High school student / government agent (Hiro); butler / bodyguard / government agent (Baymax)

Group affiliation

Big Hero 6


• (Hiro) genius polymath skilled in biology, engineering, computer programming, theoretical physics, and more
• Eyeglasses and holo specs can access his Core CyberNetwork, recording his experiences and Baymax's, displaying stored data, interfacing with the internet, etc.
• (Baymax) hydro-powered synthformer with polymantium endostructure and fueled by liquid conversion engines, possessing superhuman strength, endurance, and resistance to physical injury, advanced self-repair abilities, wide-spectrum sensors linked to Hiro's glasses, CCN, and remote recording modules he can launch, and the ability to morph into "Battle Dragon" or "Action Mecha" modes for combat, increasing in size, strength, and defensive capabilities, as well as limited flight through boot thrusters
• Occasionally uses an additional exo-structural armor called BayMaximum


The child prodigy known as Hiro was born to wealthy parents, Tomeo and Maemi Takachiho in Tokyo, Japan. Hiro’s intellectual brilliance was noticed at an early age by his parents, who started him at pre-school at only age two. Later he attended the Tesuka Advanced Science Institute, after they too took notice of the child prodigy. Hiro had a love for two things: invention, and Japan’s premiere superhero, Sunfire. For one of his science projects, Hiro created Monster Baymax, a robotic synthformer capable of turning into a dragon. Baymax was originally built to be Hiro’s bodyguard and butler. However, when Hiro’s father passed away during its construction, Hiro decided to program Baymax’s artificial intelligence with the brain engrams, emotions and memories of his father.

When Hiro was thirteen, Sunfire was at the time regarded as a fugitive in Japan after having lost control of his powers. With his hero on the run and abroad, Hiro took this opportunity to prove his hero’s innocence scientifically to his classmates and that he was not in control of the flare-ups that caused his atomic flame.  Later that same day, Hiro was approached by none other than Sunfire’s own cousin, the Silver Samurai, who had been sent by the Giri, a top government consortium made up of politicians and business entities, to recruit Hiro as a member of their new superhero team, Big Hero 6. Reluctant to accept the Samurai’s offer, Hiro was satisfied with his mother’s response after learning that she had already been approached and had respectfully declined the offer. Afterward, his mother informed him that she and his father were very proud of him and were well aware that he would one day be called upon for his intellect but they wanted him to enjoy his childhood in the meantime.

That night, Hiro was alerted by one of his inventions that Sunfire was back in Japan. Accompanied by Baymax, Hiro tracked him down to an abandoned ancient monastery in the Quonon Province. Hiro had always dreamed of meeting Sunfire but the meeting did not go as he had planned. Sunfire had returned from Canada’s Department H, where he had been diagnosed with radiation poisoning and did not have long to live. As Hiro had suspected, Sunfire was not in control of his atomic bursts and would have accidentally killed Hiro if it were not for Baymax, whose foremost programming was to protect Hiro at all costs. Automatically, Baymax transformed to his monstrous form and, despite Hiro’s best efforts, a fight almost broke out between the boy’s bodyguard and his idol. Luckily, they were soon interrupted by the Silver Samurai and the other members of Big Hero 6, Honey Lemon and Gogo Tomago. It was decided that Sunfire would return with Big Hero 6 in the hopes that they might be able to cure him. When Hiro and Baymax returned home, they found an entity known as Everwraith had kidnapped Hiro’s mother. Everwraith demanded they bring Sunfire to him, or Hiro would never see his mother again.

Hiro and Baymax broke into the Giri’s headquarters to enlist the aid of Sunfire, only to realize he was too ill to be of any use. With no other choice, the two decided the only thing left to do was to enlist Big Hero 6’s aid by joining them.  The team soon confronted Everwraith, who turned out to be a astral embodiment of all those who perished in the 1945 nuclear attacks on Hiroshima and Nagasaki. Everwraith believed the Japanese prospered from adversity and planned to use Sunfire to generate another nuclear holocaust. When Hiro’s mother was located during the fight, Hiro ordered Baymax to rescue her. However, when Baymax sensed that Hiro was in danger, his programming directed him to rescue Hiro, rather than the youth’s mother as ordered. Hiro insisted Baymax concentrate on rescuing his mother instead and, with Tomeo’s memories and emotions, Baymax managed to override his programming. Together with Big Hero 6, Hiro and Baymax defeated Everwraith and rescued Maemi. [Sunfire and Big Hero 6 #1-3]

Unfortunately for the young Hiro, his hero Sunfire left the team soon after the fight with Everwraith. Despite his original reluctance, Hiro stayed with Big Hero 6 as a member and participated on missions, such as defending Japan against “X the Unknowable,” a monster born from a child’s drawings. [Alpha Flight (2nd series) #17] They also rescued civilians during Crimson Cowl and the Masters of Evil’s weather extortion scheme that caused a freak blizzard in Japan. [Thunderbolts (1st series) #25]

Hiro’s prominence in the team increased when the Silver Samurai was presumed deceased at the hands of Elektra. Already down one member after Sunfire had left, the position of leader was appointed to Hiro, who soon filled the empty team slots with two new members, Sunpyre and the Ebon Samurai. Unfortunately, one of his first missions did not go well, as the team was brainwashed into fighting Alpha Flight. Luckily, with the Canadian superteam’s help, Hiro and his team managed to come back to their senses and the two teams parted as friends. [Alpha Flight (3rd series) #9, 12]

While he and Baymax continued to serve with Big Hero 6, Hiro still managed to continue his studies at the Tesuka Advanced Science Insititute. When the US Superhuman Registration Act passed, Japan’s premiere superheroes and protectors were more than willing to cooperate. [Civil War: Battle Damage Report] Shortly thereafter, Hiro modified Baymax’s appearance to make him look more like a traditional mecha.

One day while attending school, Hiro and Baymax found themselves attacked by mysterious supervillains, which they managed to thwart with the help of their team and newest team member, Wasabi-no-Ginger. Afterward, during his cyber investigation of the attack, Hiro met Furi Wamu, the operational head of the Exotic Assets Division of Homeland Security, who also happened to be the creator of Big Hero 6. Furi informed Hiro and Baymax that the attackers were actually just a diversion for the theft of mysterious artifacts of inestimable value and that the thieves would be heading to New York next. It was decided that, while New York had its fair share of superheroes, Big Hero 6’s responsibility was to the world, not just Japan.

The mission took Hiro and the team to Southport, New York, where the team had to remain undercover as students at Southport High School and ensure the safety of a Dr. Iosama, his daughter Marys and the priceless artifact. Marys also happened to be a genius and she and Hiro were immediately smitten with one another, confusing Baymax, who had never seen Hiro behave this way before. A distress call to Plum Island’s Research Facility brought them face-to-face with the culprit, BadGal, who had the power to possess others and used her powers to turn the team against one another. Though Hiro and the team triumphed in the end, it was not without consequences, as Baymax was heavily damaged in the battle. Worse, the battle did not go unnoticed by the authorities, who took Furi and Baymax into their custody. Things continued to go poorly when BadGal escaped, though eventually Hiro and Big Hero 6 managed to defeat her again, after which they rescued Furi and Baymax. The team remained in the States for a while but eventually returned to their homeland of Japan. [Big Hero 6 #1-5]

Back in Japan, when Big Hero 6 responded to Spider-Man's call-to-arms to stop Doctor Octopus from building satellites to raze the world, the team discovered a factory complex owned by Octavius that had been shielded. Upon coming contact with the forcefield, Big Hero 6’s first supervillain, Everwraith returned with a vengeance. With Hiro’s experience as field leader and Baymax’s upgrades, the team managed to once again defeat Everwraith and stop Doctor Octopus’ satellite from rocketing into space, almost at the cost of losing Baymax. [Amazing Spider-Man (1st series) #685, Amazing Spider-Man – Ends of the Earth]

Despite the team’s many roster changes and their reluctance to join in the first place, Hiro Takachiho and Baymax seem to be irreplaceable members as the brains and the brawn of Big Hero 6, which in turn seems to be as needed in Japan as the Avengers are in the United States. With their adventures recently taking them to the dark side of the moon, there’s no telling what will come next for this heroic duo. [All-New Invaders #7]