Big Hero 6 face their greatest challenge as Obake unleashes his plan on San Fransokyo.

In the first season finale, Obake's master plan is finally revealed and the consequences could destroy both San Fransokyo and Big Hero 6.

A trip to a haunted house on Halloween forces Big Hero 6 to face their greatest fears.

Hiro goes undercover and returns to the world of illegal bot fighting to figure out who's behind the rash of crimes committed by robots.

Fred must impersonate his father in order to save San Fransokyo from Baron Van Steamer. Hiro tries connect the dots in Obake's plan.

A Shakespeare quoting creature threatens San Fransokyo. Meanwhile, a billionaire entrepreneur stokes jealousy in the continuing rivalry between Hiro and Karmi.

After Fred accidentally reveals the identities of Big Hero 6 to Richardson Mole, Richardson blackmails the team into allowing him to join.

Hiro invents a tiny robot, Mini-Max, to supervise and be a sidekick to Fred while the rest of the team is in class.

When Karmi starts posting fan fiction about Big Hero 6, depicting Hiro as her boyfriend, Hiro is embarrassed and wants her to stop.

Honey Lemon secretly takes art classes at SFIT's rival, SFAI, and soon finds herself caught in the middle of both schools' annual Rivalry Week tradition of pranking each other.

Hiro decides to upgrade himself with super strength, but his new tech backfires and causes problems at home and at school. Meanwhile, Fred decides to buy a memento from his favorite monster movie.

Hiro becomes frustrated when he is deemed too young to attend a science workshop hosted by SFIT's most famous alumni, Dr. Trevor Trengrove.

Wasabi's need for order clashes with Hiro's chaotic work style when they collaborate on a school project.

Crazy game show host Mr. Sparkles threatens to hurt Hiro's cat Mochi to force Go Go to join a game. But she is very afraid of public appearances.

Although he is obviously ill, Hiro refuses to listen to his team-mates and Baymax and only watch from afar as they fight the Mad Jacks.

After Aunt Cass nearly discovers Hiro's secret membership in the Big Hero 6, Hiro tries to set her up with someone to distract her.

Hiro becomes demoralized when his latest school project fails spectacularly; the team must take on the incompetent villain, Globby.

Hiro, Fred, and Baymax follow GoGo into the mysterious Muirahara Woods where they get lost and everything electronic strangely fails including Baymax.

When Aunt Cass stumbles into an underground cooking competition, she thrives and becomes addicted to the excitement.

When super-villain Baron Von Steamer crashes Fred's Bro-Tillion, Big Hero 6 springs into action.

A purse thief gets more than he bargained for when he steals Honey Lemon's chem-lab purse and it turns him into a monster.

Professor Granville sets Hiro up with Karmi, a student studying biology. Karmi despises Hiro for replacing her as the youngest student to join SFIT, yet ironically, she has a crush on Hiro's alter ego which she somehow cannot seem to recognize. Meanwhile, the Big Hero 6 take on Barb and Juniper, known collectively as the electricity and pop music powered duo High Voltage. In order to help, Fred has to visit his arch-nemesis, Richardson Mole who has in his possession issue 188 of Captain Fancy. In the end, Fred's mission turned out to be in regards to Hiro's identity not being noticed and the team take out High Voltage easily. Hiro realizes that Granville set him up with Karmi to help her become more social. Karmi gains some respect for Hiro, but now thinks that he "has it bad" for her.

Set in the fictional city of San Fransokyo, 14-year-old tech genius Hiro begins school as the new prodigy at San Fransokyo Institute of Technology and sets off to rebuild Baymax. However, his overconfidence and penchant for taking shortcuts leads him and the newly minted Big Hero 6 team – Wasabi, Honey Lemon, Go Go and Fred – into trouble.