My Hero Academia depicts a daring future where superpowered Quirks are the norm, not an oddity, and becoming a superhero is a legitimate career patch with a salary, sponsors, hero agencies and adoring press coverage. In this world, however, it takes more than a good Quirk to be superhero -- one must have the right personality, too.
Powerful Quirks can help a character survive and climb the ranks, but being a hero is also about being an exemplary human being. They must set an example as selfless, brave, kind and empathetic people who will sacrifice anything for the greater good. Tsuyu Asui is one student who lives up to all this and more, and her status as Pro Hero is all but guaranteed at this point.
Tsuyu Asui, AKA Froppy: The Heart Of A Hero
Tsuyu is proof that schools like U.A. don't just test students for their Quirk-based abilities, but also their character. It's easy to take Quirks for granted in a world like My Hero Academia's, and due to the Quirk singularity theory, they grow ever stronger with each generation, meaning there is no shortage of powerful youths out there. The real test is to find students whose personalities and worldview align with that of the Pro Hero industry, and Froppy checks off every box there could possibly be.
Having been born into an entire family of frog-like people, Tsuyu is naturally comfortable with her Frog Quirk. She has spent her whole life getting used to her frog-like nature, from her weakness to cold and dryness to her affinity for water and her long, powerful tongue. This gives her a head start over characters who were uncomfortable with their gifts at first, such as Eijiro Kirishima with his "boring" Hardening ability.
Tsuyu also fulfills the "big sister" role in multiple ways, showing a selfless and mature personality that is vital for a charismatic and dependable superhero. Her home life helped shape her personality to fit the role of a hero, mainly in that she is a big sister and has often looked after her younger siblings. Tsuyu quickly learned to put others first and to never complain or set a bad example for others.
Now a student at U.A., Tsuyu is acting as a big sister once again, and her fellow students have noticed. If Tsuyu can help her mother run a full household and family, she can handle rambunctious classmates such as Minoru Mineta and the explosive Katsuki Bakugo, acting as an emotional rock and a stabilizing element. This makes her a parallel to Itsuka Kendo of Class 1-B, though it's unclear if Itsuka learned to be a "big sister" type at home like Tsuyu did.
Tsuyu Asui's Heroic Personality At Work
Tsuyu's character arc develops smoothly throughout My Hero Academia. Although she hasn't had any truly groundbreaking scenes such as mastering One For All or defeating villains like Overhaul, she's proved time and again that a proper superhero is humble but confident, kind but stern, and brave but cautious. During the clash against the League of Villains in USJ, Tsuyu teamed up with Izuku and Mineta to survive until help could arrive. Together, Tsuyu and Izuku formulated a cautious but daring plan, using their Quirks and the artificial lake to outwit the powerful villains around them.
Froppy's cool head has seen her through some serious fights, such as when she made a calculated risk and confronted Innsmouth, successfully holding him off until Selkie could arrive to finish the job. Tsuyu also handled herself well when the League of Villains' Himiko Toga confronted her and Ochaco, and she was an exemplary teammate in the mock battles against Ectoplasm as well as Class 1-B's training team. Tsuyu took part in the very first battle with Hitoshi Shinso by her side, working seamlessly with her teammates to lure Class 1-B's students into traps and knock them out (including whacking Jurota Shishida on the head with a pipe).
Likewise, it was Tsuyu who called out Izuku's squad when they recklessly ran off to rescue Bakugo from the League of Villains, tearfully explaining that if they had died during this hazardous mission, Class 1-A would have been heartbroken and severely weakened. Izuku and the others understood Tsuyu's message at once, and the entire class vowed to fight as a trusting and cohesive team, with no one running off on their own just to get killed. Tsuyu's emotional appeal brought everyone together like never before, and every superhero team needs someone just like her.