The story is set in the futuristic city of San Fransokyo and follows a young robotics prodigy named Hiro Hamada. After his older brother Tadashi dies in a tragic accident, Hiro befriends Tadashi’s healthcare companion robot, Baymax, and discovers a mysterious villain named Yokai is using Hiro’s microbots for nefarious purposes.
Hiro, along with Baymax and a group of Tadashi’s friends who have unique skills and inventions, forms a superhero team called Big Hero 6 to stop Yokai and save the city. The team includes GoGo Tomago, Wasabi, Honey Lemon, and Fred.
As they investigate, the team uncovers the true identity of Yokai – Professor Callaghan, the head of the robotics department at the San Fransokyo Institute of Technology. Callaghan seeks revenge for a personal tragedy and blames Alistair Krei, a wealthy entrepreneur, for it.
In the climax, Big Hero 6 confronts Yokai at Krei Tech’s building. During the intense battle, it is revealed that Callaghan’s daughter Abigail is alive but trapped in an alternate dimension created by the malfunctioning teleportation portal. Torn between revenge and saving his daughter, Callaghan is stopped by Hiro, who persuades him to let go of his anger.
In the end, Baymax sacrifices himself to save Abigail and Hiro by sending them back through the portal. The portal is then destroyed, seemingly taking Baymax with it. However, Hiro discovers that Baymax’s healthcare chip survived, allowing him to rebuild his lovable companion.
The film concludes with Hiro and his friends continuing their superhero adventures, and San Fransokyo is rebuilt and thriving. “Big Hero 6” received critical acclaim for its heartwarming story, diverse characters, and impressive animation.