Hiro Hamada was devestated by the death of his older brother, Tadashi Hamada, who made Baymax. After his death, and the rise of a supervillain that used Hiro's microbots, Hiro outfitted baymax and himself in robotic super suits. After the vilain was defeated, Hiro, along with the other members of Big Hero Six, protected the streets of San Fransokyo from danger.