Winner of the Oscar in 2015 for best animated feature.

Rating: Null/10 (7 March 2015)

Not doing any research at all before viewing this movie, I assumed the title referred specifically to the big, white inflatable robot. But it doesn't. The robot is Baymax, it was invented by Hiro's brother as something to make instant medical assessments and then provide care. The title is a reference to Hiro and 5 of his friends banding together, each with a different "power", to fight evil, so the six of them together form the "Big Hero 6".
Younger brother is a prodigy, Hiro Hamada. He is entering college even though he is only 14. To get into a prestigious school for gifted inventors he comes up with a small "mini-bot" that is controlled by a headband Hiro wears. But then he makes thousands of these identical mini-bots and by thought alone he can have them assemble into any shape or accomplish almost anything.
There is a fire and explosion, Hiro thinks the mini-bots and his headband are destroyed, but they in fact were stolen by the evil scientist and the fire was a cover-up. Most of the movie is about Hiro and his friends, and the Baymax, discovering the identity of the thief and defeating him.
The animation is of course superb and the animated characters are interesting. There is even a Stan Lee appearance, in animated form, in a short scene immediately after the credits finish.