Aizawa’s journey into heroism was shaped significantly during his time as a student at U.A. High. Initially a gloomy and introverted youth, he doubted his potential because his Quirk, Erasure—which allows him to nullify others' powers by looking at them—wasn't suited for direct combat. However, he was encouraged by his close friends, Hizashi Yamada (Present Mic) and Oboro Shirakumo. ​A pivotal turning point in his life was the death of Oboro during a villain attack while they were still students. This loss deeply affected Aizawa, causing him to double down on his commitment to heroism but also leading him to adopt a solitary, "underground" lifestyle. He avoids the media spotlight, preferring to work in the shadows where his Quirk is most effective. Eventually, he became a teacher, using his experiences to prepare students for the harsh realities of the hero world. ​ ​Aizawa is defined by his stoic, logical, and no-nonsense approach to life.