One of the most unforgettable scenes in "Big Hero 6" which made everyone tear up is when Tadashi Hamada died while trying to rescue Prof. Callaghan, who later became the film's antagonist. Now Tadashi will be back in "Big Hero 7," but reports says he would also become an enemy and would face off with his very own little brother, Hiro.

According to International Business Times, Prof. Callaghan's survival led to the theory that Tadashi might have also survived the flames. The professor escaped the flames using the microbots created  by Hiro which he presented in the school fair, but who knows? Tadashi might have used it as well!

However, it is also Prof. Callaghan's evil nature that made fans believe that Tadashi may become an enemy. The report further said that Tadashi's body was never found on "Big Hero 6" so it is not confirmed that he is really dead, and he will return in "Big Hero 7"

Fans believe that the explosion could have transformed Tadashi into Sunfire, an original character from the Japanese manga, "Big Hero 6," where the movie took its inspiration.  After some serious brother squabble, Tadashi is expected to be joining Hiro as the team's new and seventh member.

The 3D animated superhero-comedy film produced by Walt Disney was first released in the Tokyo International film festival on October 23, 2014 and at the Abu Dhabi film on October 31 before its theatrical release on US on November 7, 2014. The movie was considered the highest grossing animated film of 2014 earning more than $657 million worldwide. It also won the Academy award for Best Animated Feature and Kid's Choice Award.

"Big Hero 7" is expected to be released by the third quarter of 2017, with original casts from "Big Hero 6" reprising their role which includes; Hiro Hamada (Ryan Potter), Baymax (Scott Adsit), Fred (T.J. Miller), GoGo Tomago (Jamie Chung), Wasabi (Damon Wayans Jr.) and Honey Lemon (Genesis Rodriguez).