When it comes to My Hero Academia's teachers, Shota Aizawa still manages to stand out as one of the strangest choices. He doesn't seem all that interested in teaching, and often brings a sleeping bag to class. He's not particularly good with students, either, so how did he end up with this job? The answer to that question is simple: he didn't ask to be a teacher.
In addition to being the teacher of Class 1-A in My Hero Academia, Aizawa is also a major character in My Hero Academia Vigilantes, the prequel/spinoff series that was written by Hideyuki Furuhashi and drawn by Betten Court. Vigilantes, unlike some of the other spinoffs, is canon, and gives a great look at what some of the pros and other older characters of MHA were like when they were younger. For Aizawa, not much has changed over the years, and he's as grumpy and quiet then as he is in the series' present day.
My Hero Academia: Vigilantes Reveals Aizawa's True Backstory
In a bonus chapter of Vigilantes, known as Chapter 6+Alpha, the pro heroes in the area are called to the police station to discuss the outbreaks of "Instant Villains" that have been occurring. "Instant Villains" aren't really villains at all, it turns out, but rather innocent people who had been exposed to the Quirk-boosting drug known as Trigger. The heroes discuss strategies and as the meeting ends, Aizawa walks out with Midnight, sarcastically referring to her as a guidance counselor for her caution. She tells him she plans on doing just that and becoming a teacher at UA, stating that Principal Nezu requested her specifically. She offers an innuendo-laden explanation of her teaching philosophy before they're interrupted by a suicide bomber bursting into the police station. While Endeavor loses it in anger and nearly sets the bomber off, Aizawa snatches him with the capture cloth and Midnight uses her powers to put him to sleep, proving what a good team they can make. The next day, Aizawa gets a call from Midnight, telling him that she put in a good word for him with Nezu, and that he's very interested in having Aizawa as one of My Hero Academia's UA teachers.
Aizawa Rarely Makes His Own Decisions in My Hero Academia
While Aizawa wasn't looking for a teaching position and isn't enthused about the offer, he obviously did take it eventually, as did Midnight and his other friend Present Mic. Vigilantes takes place over several years, so a fair amount of time passed before Aizawa became a teacher. Did he simply give in to pressure? It wouldn't be the first time; Aizawa's hero name in My Hero Academia, Eraser Head, was made up by Present Mic when they were students in UA, and Aizawa simply went along with it. In fact, it seems like Aizawa almost never makes big decisions in his life by himself, instead letting himself drift along with the currents of life. He wound up at Prince's Hero Agency just going along with Midnight and his deceased friend Oboro Shirakumo, too. It's no surprise that his friends would pressure him into accepting a job at UA with them, too.
Aizawa's Quirk makes him an excellent choice for students who can't yet control their powers well, and his harsh training methods have produced results. Although Aizawa may not have chosen this life in My Hero Academia, there's no denying that he has a certain knack for it, and just maybe, he's pretty happy there, too.