Izuku is a very timid, helpful and polite boy, frequently overreacting to abnormal situations with exaggerated expressions. Due to being bullied since childhood for being born without a Quirk, he is initially portrayed as insecure, being more reserved and not self-expressive, especially in front of Katsuki Bakugo, who constantly subdued him for his aspirations to be a hero. However, after being accepted into U.A. High, making new friends and facing Katsuki during the Battle Trial Arc, he has gradually turned into a more confident and brave person, to the point of developing some leadership skills. Izuku is a caring person, and will never hesitate to rescue someone in danger, even if he knows that he's not strong enough to do it. Often, he does this in a whim, taking a more careless approach than usual. Izuku has also shown to be selfless enough to try to help people with personal, emotional problems, even if it doesn't concern him, claiming that a hero is someone that meddles on the lives of other people.