In 1870s America, a peaceful American settler kills his family's murderer which unleashes the fury of a notorious gang leader. His cowardly fellow townspeople then betray him, forcing him to hunt down the outlaws alone.
A witch tasks a childless baker and his wife with procuring magical items from classic fairy tales to reverse the curse put on their family tree.
In the year 2000, Ki Ha-myung is leading a happy life with his parents and older brother Jae-myung, until his father Ki Ho-sang, the captain of the firefighting squad, dies in a factory explosion during a rescue attempt along with several of his men. When Ho-sang's body is initially missing, the media sensationalizes the case by scapegoating him. In a battle for ratings, cold and calculating MSC reporter Song Cha-ok alleges that Ho-sang survived the blast, and is currently in hiding because he was responsible for the deaths of his men.
A man believes he has put his mysterious past behind him and has dedicated himself to beginning a new, quiet life. But when he meets a young girl under the control of ultra-violent Russian gangsters, he can't stand idly by - he has to help her.
The special bond that develops between plus-sized inflatable robot Baymax, and prodigy Hiro Hamada, who team up with a group of friends to form a band of high-tech heroes.