Summary
Katsuki Bakugo is one character that anime fans cannot ignore. His character development throughoutMy Hero Academiais quite remarkable. Bakugo is a bully, and has been one right from when he was young. In addition, he is quite arrogant and has a short temper, which makes people avoid him.
But one person Katsuki cannot seem to get rid of with his bad personality is Izuku Midoriya. Katsuki treats Midoriya badly, and soon, fans come to understand that he is the way he is because he feels weak and insecure. Katsuki wants to be better than everyone, but unfortunately, some of his peers at U.A. High are far more skilled and powerful than him. This infuriates him and causes him to throw a tantrum. But as theMy Hero Academiaseries progresses, he soon learns to become less aggressive and more open towards people. And in doing so, he is able to grow and maintain meaningful friendships at U.A. High.

4Denki Kaminari
Kaminari did not like Bakugo upon meeting him because of Bakugo’s bad attitude, and more importantly, because he is a bully. Fortunately for Bakugo, Kaminari sees past his attitude and starts teasing him, which makes Bakugo angry.
Kaminari and Bakugo might not be the closest, but they interact a lot because of Kirishima, who is friends with both of them.They had to work togetherduring the Final Exam, and Bakugo tells Kirishima that he has to master his quirk to become stronger. Kaminari takes this advice seriously, andmakes notable progress with his quirk. AsMy Hero Academiaprogresses, Kaminari becomes more open with Bakugo and even gets away with calling him ‘Kacchan,’ a name only Izuku Midoriya calls him.

3Shoto Todoroki
Katsuki sees Todoroki as a rival, while the latter could not care less. This infuriates Bakugo. Shoto is calm and cool-headed, while Bakugo is hot-headed. Their encounter at the sports festival infuriated Bakugo so much that he was put in chains by the teachers. Todoroki and Bakugo are paired up duringthe Sports Festivalto fight, but Todoroki is fighting with justhis cold quirk. Although Bakugo wins the fight, he is not satisfied because he knows that Todoroki did not show his true abilities.
Bakugo eventually gets over the fight, and accepts his unworthy win. He has conversations here and there with Todoroki, and Todoroki considers him his friend even though Bakugo is too proud to admit it. Todoroki is among those who set out to rescue Bakugo when he gets taken away by theLeague of Villians. After this, Bakugo still sees Todoroki as a rival, but in a friendlier way. Now, they are both focused on getting stronger to fight against villains and protect their friends, especially Deku, from Shigaraki.

2Izuku Midoriya
Bakugo initially feels threatened by Midoriya because ofhis brave and heroic nature. Bakugo could not understand why Midoriya had such a heroic personality even without having a quirk. Instead of being more selfless and brave, Bakugo resorted to bullying Midoriya to make him feel weak and less than himself. As Midoriya attends U.A. High alongside Bakugo, he tries to make life unbearable for Midoriya, but cannot.
Over time, as they fight and have conversations, Bakugo becomes warmer towards Midoriya and vows to defeat him one day now that he has All Might’s powerful quirk. This vow drives Bakugo to become stronger, and also to protect Deku from Shigaraki and other villains. Bakugo is the one responsible for giving Midoriya the name ‘Deku,’ which means ‘good for nothing.’ As part of getting more warm towards Midoriya, he refrains from calling him Deku and tries to call him by his first name, Izuku.

1Eijiro Kirishima
Kirishima is the one individual who is able to look past Bakugo’s temper and aggressiveness. In fact, he respects him because of his nature, and it makes him see Bakugo as more masculine. Although he gets tired of Bakugo’s temper sometimes, he still cares for him. This friendship is definitely not one-sided, as Bakugo has shown time and time that he values having Kirishima in his life. For instance, he repays Kirishima the money he spent on night vision goggles in the hope that they would come in handy when he goes to save Bakugo from the League of Villains. During the time that Bakugo is away, Kirishima is ready to break the rules and go after the League of Villains himself to save his friend.
What makes their dynamic duo work is the fact that Kirishima listens to Bakugo. They both want to get stronger, and they encourage each other to do so. More importantly, Kirishima is the only person who can get Bakugo to do something or change his opinion about something, like when their classmates gather at the school pool. Bakugo is initially against the idea and does not want to go, but Kirishima encourages him to tag along, and he does so much to the surprise of everyone.