Shouta Aizawa

Shota is a very stern and reserved man who has lofty expectations of his students. He is primarily motivated by logic and does not believe in the necessity to maintain a clean-cut appearance or filter his words or ideas for others. He often comes off as cold, apathetic, and impatient, exerting very little energy in most situations, preferring to take naps in his sleeping bag instead.[5]

During his time as a student at U.A. High School, Shota was a gloomy and introverted young man who held severe doubts over whether he could be a hero, as his Quirk, Erasure, while useful, couldn't do much by itself. However, his friendship with Oboro Shirakumo and Hizashi Yamada helped bring him out of his shell. Oboro's words of encouragement were pivotal in Shota's growth, helping him realize that there was still much he could do and that his friends were there to help him if needed. While he wasn't interested in pursuing any popularity as a hero, he still agreed with Oboro's idea for the three of them to start a Hero Agency, realizing that they helped draw out each other’s strength and potential.

Shota begins his Pro Hero career as Eraser Head. Shota begins his Pro Hero career as Eraser Head.

However, everything changed after Oboro was killed in a fierce attack by the villain known as Garvey. The grief of losing his close friend strongly impacted Shota and caused him to lock in on his commitment to becoming a hero. However, this also caused him to develop his solitary tendencies, barely interacting with any of his classmates, and taking breaks by napping in his sleeping bag. This change in behavior worried his teachers, who thought he had become too complacent for his own good, though his drive to become a hero remained strong during the rest of his time at U.A. While his teacher advised him not to rush his career, upon graduating from high school, Shota made the decision to become an underground hero who would specialize in fighting villains, leading to him becoming the serious and driven man that he is now, Eraser Head.

Prior to becoming a teacher at U.A. High, Shota had a more reckless and apathetic demeanor as a Hero. While still taking his duties seriously, he was willing to overlook the illegal actions of the Naruhata Vigilantes along with unethical yet well-meaning dealers such as the Hotta Brothers. He even allied himself with them multiple times in order to help take down the Villain Factory. Despite this, he didn't hesitate to try to arrest Koichi Haimawari when the latter was wanted by the police, telling the young Vigilante that he was being reckless by resisting the Pro Heroes who wanted to help and believing that he wouldn't stop until someone got hurt. Even so, he soon abandoned his attempt to arrest him so the two of them could fight Number 6 and his army of Anonymous together, though he still warned Koichi that he would break his legs if he tried to run away.

Shota's tendency to lay inside his sleeping bag. Shota's tendency to lay inside his sleeping bag.

As a teacher with notoriously high expectations, Shota is known to expel students who he feels are not suited for U.A. High. However, it's revealed that this high expulsion rate is only on paper and that he actually re-enrolls the students he expels: Shota does this so they can experience "death" once, giving them an experience that drives them to push even higher,[14] although it is noteworthy that he has not expelled any students from Class 1-A yet, despite being well-known for doing so.[15] He can be rigid and strict when necessary and has little tolerance for disobedience. Shota is not afraid of putting his students through rigorous training and often emphasizes the more unpleasant parts of heroism so that his students can overcome their limits.

Shota has proven to be very vocal and unafraid when expressing his ideas. He has mentioned on several occasions that some of U.A.'s choices when it comes to examinations are not practical or challenging enough for real hero hopefuls and is adamant about having certain systems used by the institution changed.[16] He also blatantly stated that he did not believe Izuku Midoriya could become a hero when they first met.[6] He is also known for lying to his students in order to manipulate them into giving their best, a technique he describes as a "logical ruse" or "rational deception".[17]

Shota's impression on his students. Shota's impression on his students.

Despite his apathetic traits, Shota genuinely cares about his students and will go to great lengths to protect them. As Eraser Head, he saved Tsuyu Asui from being decayed by Tomura Shigaraki, in spite of his grievous injuries.[18] He has also expressed belief in his students on multiple occasions and is confident that even the likes of Katsuki Bakugo would not be swayed by Villains.[19] Recovery Girl even implied that he allowed himself to be captured by Momo Yaoyorozu during her First Term Final Exam in order to boost her confidence.[20] Shota is also quite nurturing, as he has been seen attending to his duties as Eri's temporary guardian without complaint; he has demonstrated to be very attentive and involved in his role as a provider even outside of his duties as a teacher and mentor.

Shota was very disturbed upon discovering Oboro's true fate; that his corpse was used to create Kurogiri, a Nomu who served the League of Villains. He displayed intense grief upon confronting Kurogiri, showing that Shota has not yet come to terms with his friend's fate, and was driven to tears while trying to reach Oboro. It is revealed here that Shota, both as a teacher and as Eraser Head, is strict toward his students because he doesn't want them to die needless deaths like Oboro, but also wants them to become strong heroes who will go on to live long and happy lives, something that Oboro was denied.

Shota declares he will live to see his students graduate and become Heroes. Shota declares he will live to see his students graduate and become Heroes.

Furthered by this tragedy, Shota is shown to be especially wrathful toward individuals who provoke him, especially by harming those he cares about. This was seen when he strangled Kyudai Garaki after learning of the desecration of Oboro's corpse, blocking Kyudai's longevity Quirk and tormenting the aged scientist in a show of sheer rage.

Despite his personality, Shota has shown on several occasions that he is not completely devoid of joy or humor: he often grins whenever he is impressed by one of his students[6][21] or after he tricks them with one of his "rational deceptions."[15][17]

Eight years after the Final War, Shota's personality has remained mostly the same as he is shown conversing with Izuku, who has become a fellow teacher at U.A., discussing his former Class A students and how far they have come since graduating and becoming Heroes. Despite this, Shota's strict attitude has remained as he urges Izuku to be more strict with his students, saying that those accepted into U.A. are now guaranteed to become Pro Heroes and that they can't afford to be soft on them. Ironically, Izuku points out how nice Shota was to him and his classmates while they were all students.[2]