Aizawa's teaching philosophy stemmed from his trauma and loss of his best friend, Shirakumo. Shirakumo's death greatly affected Aizawa, leading him to isolate himself and become an underground hero.

The first Nomu ever created was Kurogiri, a high-end Nomu who was created with the corpse of Oboro Shirakumo, a U. A High student who was killed during a battle with a villain during his hero-work ...