Warning: Spoilers ahead for the anime and manga.
Now before I begin I just want to say I understand the Bakugo has a superiority complex and I know why he hates Deku but that does not take away from the fact what he has done and how it has shaped him.
The story starts with our main hero Deku, an underdog who is constantly abused by his childhood friend Bakugo. At first I believed that Deku came out relatively unharmed by this bullying, but as the series progressed it has become apparent the bullying has left deeper scars than I originally thought.
When Azawia is discussing the relationship between Deku and Bakugo with how they interact when paired up in a team. “They’re on horrible terms.” He points out. This statement shares the blame equally between the two which is completely unfair to Deku. Bakugo’s superiority complex at the time made it impossible for other people to get along with him and the only person who can get close is with someone who can figure him out and is not afraid of him or in other words a complimentary personality.
It was at this point I came to realise that none of the teachers (except All Might but he doesn’t really press Mydoria on it) know about Bakugo bullying Deku or just don’t address it as far I can see. The students know something happened between the two but they don’t delve in to it deeply with just a brief moment where Ochako says “I remember now…it’s Bakugo who keeps bullying you.” But beyond that nothing with the other students. While some of the faculty know about Deku inheriting his power from All Might none of the students do (except for Bakugo but that’s later on and not really important because he was the one bullying Deku in the first place), there all assuming that Deku has had his powers since he was a kid. The students are completely unaware that just before the entrance exam he was quirkless and have no idea that he was bullied by Bakugo so mercilessly that he visibly flinches whenever he uses his powers around him and when he see’s Bakugou approaching he prepares for an attack from him.
He’s been constantly bullying Deku since preschool and soon after other kids began to join in. In the series the bullying is seen as both physical and mental which can greatly harm a person. In Deku’s case he develops feelings of inferiority which he constantly battles against as Bakugo is always right behind him trying push him beneath his boot heal. His torment goes to the point where he advises Deku on committing suicide saying, “If you want a quirk so damn badly, just throw yourself off the fucking roof and hope you get one in the next life!” The scene plays out lightly to me but it is far darker than I imagined as it’s confirmed by Deku mulling over his words as he does say it was suicide he was talking about.
When Bakugo got a flashy quirk while his other classmates got rather useless one’s, this solidified his place at the top of the hierarchy of the classroom making the other peons follow him out of awe as in this world whoever has the flashiest toy is the leader and whatever he says is immediately law. His reasoning for his torment of Deku was for a perceived slight when Deku tried to help him up when he fell down in the water, he saw this as Deku looking down on him and that is when the torment began. As the other children saw Bakugou beat down Deku him for not having a quirk and like the ever-present sheep they are the students join in on the torment that lasted till Junior High.
Previous flashbacks indicate that most of the kids that were in Deku and Bakugo’s preschool were also in their junior high school classes. As weird hands and shark haired guy hang out with Bakugo after school when they get attacked by the slime villain. These are the same individual’s who were around him when they were beating that kid up at the park. From the time they were in preschool till Junior High Deku has been constantly put down, beaten up and isolated from most kids his age as till up to High School Deku has not made any friends other than Bakugou.
Deku knows this isn’t how other kids are treated by there fellow peers and desires the same treatment that everyone else gets. Not knowing how to go about it he looks at heroes who are admired, loved and adored by the public specifically the top hero All Might. All Might is adored by everyone as the number one hero, who wouldn’t want to be like him but this has caused some issues. All Might over the years has put himself in extremely dangerous situations and portrayed as self sacrificing by the media. Putting everyone else above his own safety. Now I can practically hear you saying this is what hero’s do but there is a difference between being selfish and not caring about yourself and All Might is walking that line.
All Might has even damaged himself to the point where he can’t use One For All anymore. It is a repetitively hammered in fact that in this world hero’s must sacrifice to protect and be willing to do anything to save the day.
Deku worships All Might like a god and with no father around because we see no hide or hair of Deku’s father ever, he starts to mould himself in his idols image as he is the closet to a dad he has ever had.
The bullying followed by his hero worship of All Might has forced Deku into a mindset that we see very often, the sacrifice of self. He has damaged his body for the sake of everyone else. His arm is covered in scars, his bones have been broken repeatedly. While in his mind he breaks his body to protect people and win the love of his hero but in the end he views himself as someone who needs to constantly put others first no matter what.
This self destructive way of thinking has caused irreversible damage to himself and it is only with the retirement of All Might and a reminder of his past failures that he has vowed to not damage himself anymore, I just hope the change is permeant and not just a fleeting thought otherwise good bye pro hero dreams.