Momakase blackmails Hiro into helping her steal a mysterious item from Yama's safe, threatening to tell Chief Cruz Big Hero 6's secret identities if he doesn't help her.
As the new prodigy at San Fransokyo Institute of Technology, Hiro now faces daunting academic challenges and the social trials of being the little man on campus. Off campus, the stakes are raised for the high-tech heroes as they must protect their city from an array of scientifically enhanced villains.