Another interesting plot could be that some sort of dark force is affecting both the Naruto and Street Fighter worlds. Characters from both sides have to team up. For example, Ryu could teach Naruto how to better control his chakra in his attacks, while Naruto shows Ryu how to use shadow clones in combat strategies. This would lead to a lot of character development and exciting battles.
One idea could be a crossover tournament where Naruto characters like Naruto, Sasuke, and Sakura enter the Street Fighter universe to compete. They could learn new fighting styles from the Street Fighter characters and form unique friendships or rivalries.
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.
One idea could be to have Ruby Rose learn new combat moves from a Street Fighter character like Ryu. She could incorporate his hadouken - like move into her scythe attacks, creating a unique and powerful fighting style.
One idea could be a crossover between Street Fighter and a popular anime like Naruto. Imagine Ryu training with Naruto to master new forms of energy control. Another could be a crossover with the DC Universe, where characters like Chun - Li team up with Wonder Woman to fight a common enemy. Or perhaps a crossover with the world of Final Fantasy, with Street Fighter characters embarking on a magical quest in a fantasy realm.
One idea could be creating an OC who is a long - lost relative of an existing character, like a cousin of Ryu. This OC could have a unique fighting style that combines elements of Ryu's Hadoken but with a different twist, like a lightning - infused version. Another idea is an OC from a different dimension who comes to the Street Fighter world to learn their fighting techniques. They could start off as a bit of an outcast but gradually gain the respect of the other fighters.
One idea could be to create a story where Naruto discovers a new and powerful fighting style from an ancient scroll. Another could be a fanfiction about a tournament among all the ninja in the Naruto universe, with unique rules and unexpected alliances. Or perhaps a story where Naruto has to fight an enemy who can copy his every move and he has to find a way to outwit them.
One idea could be Poison joining the Street Fighter tournament to prove herself. She might face off against some of the well - known Street Fighter characters like Ryu or Chun - Li. Another plot could involve Poison teaming up with a Street Fighter character, say Ken, to take on a common enemy that threatens both their worlds.
A third plot idea is a crossover with the 'Final Fantasy' universe. Ryu could be transported to a world filled with magic and monsters. He would have to team up with the Final Fantasy characters to fight against a common enemy, perhaps using his Hadouken in combination with magic spells.
A really interesting fan fiction could be about the backstories of the female fighters in Street Fighter. For instance, Chun - Li's journey to becoming a strong fighter while also dealing with the expectations of her family and society. You could explore her relationships with other characters and how she overcame various obstacles in her life to be where she is in the game.
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 possible plot could be that Naruto, through some sort of interdimensional rift, ends up in the Street Fighter universe. There, he meets the female characters like Chun - Li, Cammy, etc. They initially see him as an oddity but gradually become attracted to his tenacity and unique ninja skills. Naruto, in turn, is both bewildered and intrigued by these new and powerful women, and they form a sort of harem around him as they go on adventures together, fighting common enemies and learning from each other's fighting styles.