|Voice actors||(Ja:) Yūtarō Honjō|
(En:) Ryan Potter 
|Origin||Big Hero 6|
|Game||Kingdom Hearts III|
|Kingdom Hearts III|
|Big Hero 6 (2014)|
A boy genius living in San Fransokyo, and a member of Big Hero 6. After Hiro presented the microbots he invented, events took a turn for the tragic and he lost his brother, Tadashi.
Together with Tadashi's friends and his brother's robot, Baymax, Hiro got to the bottom of the incident, and now the team continues to keep the peace as Big Hero 6.
- "He wanted to help people. Now we do what we can."
- —Hiro, about how Big Hero 6 carries on his brother's dream.
Kingdom Hearts III
At Hiro's garage, Hiro introduces Big Hero 6 to Sora, Donald, and Goofy. To help with the Heartless problem, Hiro gives Sora an AR device, which allows him to communicate with Sora wirelessly throughout the city. Hiro stays in his garage to coordinate the team as the rest of Big Hero 6 fight in the city.
While the whole group rests to eat ice cream at the bridge, Hiro tells Sora about his deceased brother Tadashi. Hiro says he is still alive, in a way, because of how much he has inspired and influenced them.
At night, the city is attacked by Darkubes, which Hiro mistakenly identifies as Microbots, his old invention that he believed were destroyed. Hiro returns to his garage in order to see if there are any leads as to who is controlling them. During a fight with the Darkubes on a roof, Hiro returns and meets Dark Riku, who refuses to return Baymax's chip to Hiro.
The next day, when Dark Baymax is defeated, Hiro contemplates destroying Dark Baymax's infected chip, although he uses his resources to save the original Baymax. Sometime after Xehanort's defeat, Hiro and Baymax manage to stop a car from falling off the edge, but were unable to rescue the other car until the other Baymax rescued it. After the team saved the civilians, they strike a pose to the cheering crowd.
Hiro is a half-Japanese half-Caucasian teenage boy with black hair and brown eyes. He normally wears a blue hoodie jacket, a red shirt with a humanoid robot on it, long dark beige cargo capri shorts, and dark brown Converse sneakers with yellow laces. When fighting alongside Big Hero 6, he wears purple armor with black and red highlights.
Hiro is extremely intelligent, creating devices like Sora's AR headset. He is not much of a physical fighter, providing support like directions in the safety of his garage to Sora and the rest of Big Hero 6. In short, he works as Big Hero 6's tech support; though in the field, he usually gives Baymax instructions in what takes priority, akin to a coach encouraging an athelete, and flies on his back, acting as the team's "eye in the sky". His brilliance is best shown with Big Hero 6's superhero suits, which he created by incorporating aspects of their science projects, and is able to upgrade their suits after they take inspiration from Sora's fighting style.
Hiro is devoted to the memory of his late brother Tadashi, and so takes a stand against violence and destruction, especially that caused by the corruption of Tadashi's invention, Baymax.
In Big Hero 6, Hiro is an intelligent teenager who participates in illegal robot fights. His older brother Tadashi encourages Hiro to join his university's robotics team. Hiro does so and works on his project called microbots, which are swarms of tiny robots that can link together in any arrangement imaginable using a neurocranial transmitter. When Tadashi dies in a building explosion, Hiro becomes distraught, but motivated to continue Tadashi's dream of creating the ultimate healthcare robot, Baymax. When Hiro discovers that his microbots had been stolen he realises the thief "Yokai" may have been responsible for Tadashi's death, he teams up with the university members to form Big Hero 6, a group dedicated to stopping the villain.