Hiro Takachiho was born a child prodigy with a super-genius intellect. The son of wealthy industrialist Tomeo Takachiho and Maemi Takachiho he was raised in the rich Tokyo suburb of Yoga, City of Setagaya. His parents recognised their son's intellect at a early age, he was in pre-school at age 3. Hiro is one of the world's most brilliant child prodigies and was accepted into the private Tesuka Advanced Science Institute. It was there that young Hiro's aptitude for invention was discovered.
Hiro is an 11-year old genius whose father died when he was young. To partially replace him, he created Baymax, a robotic bodyguard. He was also a huge fan of Japan's greatest known hero, Sunfire.
Big Hero 6
When Big Hero 6 (Japan's official super-team) began to form, Hiro was drafted. He refused initially but after an incident wherein his mother was held hostage and BH6 rescued her. Hiro reluctantly joined to prevent Everwraith from slaughtering millions in downtown Tokyo. During the battle, Big Hero 6 was joined by Sunfire, Japan's premiere super hero and a mutant with the ability to super-heat matter into plasma, who was instrumental in the Everwraith's defeat.
Soon after, Big Hero 6 moved their headquarters from the Giri Office Building to Japan's Cool World Amusement Park, where they were attacked by X the Unknowable, a monster born from a child's drawings that could transform its atomic structure into any form and shape. With the help of Alpha Flight, Big Hero 6 destroyed X the Unknowable in the fires of Mount Fuji. Afterwards, Big Hero 6 continued to protect Japan from all threats, such as when the team rescued Tokyo residents from a freak blizzard caused by the Crimson Cowl (Justine Hammer) and her Masters of Evil.
The members of Big Hero 6 fell victim to a mind-control device implanted within Baymax. Travelling to Canada, the mind-controlled super heroes attacked a new incarnation of Alpha Flight at a national park. After a brief battle, the mind-control device was short-circuited and the two teams parted as friends. Big Hero 6 returned to Japan to seek out the parties responsible for their mind-control.
Big Hero 6 help Alpha Flight protect the timestream.
Spider-Man rallies many of earth heroes including Big Hero 6 to help stop the construction of Doctor Octopus' satellites.  Big Hero 6 found one of the facilities, discovered that it is guarded by Everwraith. Despite a tough battle, Big Hero 6 finally ended up victorious.
Super-Genius Intellect: Hiro has an intelligence classed as super-genius, he easily is one of the smartest people on Earth. Furthermore, this extends to his remarkable ingenuity dealing with difficult situations such as difficult foes and deathtraps where he is capable of using his available tools. He is an excellent engineer and mechanic capable of fixing almost any, if not all machinery.