Another plot could involve a character from My Hero Academia, like All Might, training with a Street Fighter character like Ryu. All Might could teach Ryu about heroism while Ryu could show All Might some new fighting techniques. This exchange of skills and values could be really interesting to explore.
One idea could be that the heroes from My Hero Academia are transported to the Street Fighter universe. They could participate in the Street Fighter tournaments, with their quirks adding a new dimension to the fights. For example, Deku could use his One For All to perform amazing acrobatic attacks.
Maybe some of the villains from Street Fighter, like M. Bison, could make their way into the My Hero Academia world. This would cause chaos as the heroes there have to deal with a different kind of threat. The heroes would have to learn about the fighting styles of the Street Fighter villains quickly to stand a chance.
One idea could be having the characters from My Hero Academia participate in the Street Fighter tournament. For example, Deku could use his One For All power in the fighting matches. Another idea is a team - up between Ryu and All Might to fight a common enemy. Maybe they could face a villain who has the ability to steal powers, like All For One, but also has the combat skills of the toughest Street Fighter villains.
One idea could be that Naruto characters are transported to the Street Fighter universe and have to learn the fighting styles there. For example, Naruto might be intrigued by Ryu's Hadoken and try to incorporate it into his own Rasengan. Another could be a tournament where both Naruto and Street Fighter characters compete. Sakura could face off against Chun - Li, with Sakura using her medical ninjutsu in unique ways during the fight.
Perhaps there could be a story where the dark forces in Mortal Kombat are trying to corrupt the pure - hearted characters in Street Fighter. Akuma might be a target for this corruption. The Mortal Kombat villains could offer him more power in exchange for his loyalty. The other Street Fighter characters would then have to try and save Akuma from this dark influence, and they might seek help from some of the more morally ambiguous Mortal Kombat characters.
One idea could be a crossover where Gon and Midoriya meet and have to team up to face a new villain that combines the nen and quirk powers in a dangerous way. Another could be a story where Hisoka somehow ends up in the My Hero Academia universe and starts causing chaos among the heroes and villains there. A third idea might be a fanfic where Ochako discovers nen abilities and tries to incorporate them into her hero training.
A different plot might be that the yandere is a childhood friend of Izuku who was always in the background. As they grow older and Izuku becomes more involved in the hero world, her yandere feelings surface. She starts to collect mementos of Izuku secretly and becomes extremely jealous of any girl who shows an interest in him, leading to a lot of drama and conflict within their friendship circle.
One idea could be that in an alternate universe, Bakugou and Toga are forced to team up during a villain - hero cooperation event. They start off hating each other but gradually come to understand each other's motives. Another could be a situation where Toga takes on Bakugou's appearance to get closer to the other heroes and ends up having some really strange interactions with Bakugou himself. Maybe she tries to use his appearance to cause chaos but then realizes she doesn't really want to hurt him in the process.
One idea could be that the characters from My Hero Academia end up in the world of Highschool DxD. They could have to deal with the devils and angels while also trying to figure out how to get back to their own world. Another could be a crossover of the power systems, like a Quirk user from My Hero Academia having to fight using the Sacred Gears from Highschool DxD. Or perhaps a team - up between the heroes and the devils to face a common enemy that threatens both their worlds.
One idea could be that they are paired for a difficult hero training mission. Tokoyami's dark powers and Tsuyu's unique abilities would have to work in harmony. Maybe they get trapped in an area where Tokoyami's darkness actually helps them hide from a powerful enemy, while Tsuyu uses her long tongue to reach for resources or communicate with allies outside the area.
Well, here's a plot. Toga has a vision in which Uraraka is in danger from a new villain. She decides to protect Uraraka, even though they are on opposite sides. Uraraka is initially suspicious but then realizes that Toga is being genuine. This could lead to a strange friendship where they have to keep their relationship a secret from both the heroes and the villains. They could then start to influence each other in small ways, like Uraraka teaching Toga about the value of friendship and Toga showing Uraraka that things aren't always black and white.
One idea could be that they are paired up for a special training mission. During the mission, they face various challenges that force them to rely on each other's unique quirks. Mina's acid can be used to break through barriers while Kirishima's hardening can protect them from attacks. This shared experience deepens their bond and they start to realize their feelings for each other.