Obake unleashes his master plan upon San Fransokyo, bringing about destruction to the entire city unless Big Hero 6 stops him once and for all.
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.