Bakugou might react with his usual anger. He could lash out at the bullies verbally or even physically, which might make the situation worse. For example, if someone makes a snide comment, he could respond with a loud and aggressive retort.
Bakugou might be initially shocked. He's used to Izuku calling him 'kacchan' for so long that it's become a normal part of their relationship. So, when Izuku stops, it could throw him off balance.
Some characters might try to understand Deku's motives. Kirishima, who was close to Bakugou, would be angry at first but might also try to find out if there were any extenuating circumstances. However, many would be afraid of Deku, seeing him as a threat now that he has killed one of their own.
Deku might be completely shocked at first. Since Bakugou has always been so aggressive towards him, he would never expect such a confession. He might just stand there, mouth agape, not knowing what to say.
Maybe in this fanfiction, the class 1a students from the present time travel to the future and meet an older, more mature Bakugou. He could be a pro - hero now, and they are amazed by how much he has changed and grown. He might show them some new and powerful moves that he has developed over the years.
In some fanfictions, the bullying of Bakugou by Class 1A might be a part of a bigger plot where there is an external force influencing the class's behavior. For example, a villain could be using some sort of mind - control or misinformation to turn the class against Bakugou. Bakugou, in this situation, would have to fight not only against the bullying but also against this external threat. As the story progresses, the class could break free from the influence and realize their unjust actions towards Bakugou, leading to a big reconciliation scene.
The teachers, especially Aizawa, would also be worried. Aizawa might give Bakugou special permission to skip classes or training until he's recovered. He'd also keep an eye on Bakugou's progress and make sure he's taking care of himself.
Eventually, he might come to accept it in a grudging way. If Izuku is wearing the clothes for a good reason, like in a team - up situation where it's part of a strategy, Bakugou might tolerate it. But he'll still probably make some snarky comments about how Izuku better not ruin his clothes.
Eventually, the class might come to understand Marinette's decision. As they struggle to do things on their own, they realize how much effort Marinette had been putting in. This could lead to them changing their ways and maybe even trying to make it up to Marinette if she decides to start helping again.
If it's a fanfiction about Class 1A meeting Bakugou's boyfriend, there could be a lot of comical moments. Maybe Mineta would try to be inappropriate and get scolded by Bakugou. The more responsible students like Iida might give Bakugou relationship advice. His boyfriend could be from another class or even another school. If he's from another school, Class 1A would be curious about the differences in their hero training. And Bakugou would have to balance his relationship with his training and his place in Class 1A.