Well, in a fanfiction world, it could happen if there was some sort of cross - dimensional or time - traveling event. Maybe Naruto stumbles upon a portal that leads him to the world where the Hiten Mitsurugi - Ryu exists. There, he meets a master of the style who sees potential in Naruto and decides to teach him.
His speed would likely increase significantly. The Hiten Mitsurugi - Ryu is known for its fast and fluid sword movements, so Naruto would need to adapt to this new speed. He might start using more acrobatic maneuvers during combat, like leaping and spinning in ways he didn't before.
One popular Hiten Mitsurugi - Ryu Naruto fanfic could be one where a character uses the techniques from Hiten Mitsurugi - Ryu in the Naruto universe in unique ways. For example, they might combine it with ninjutsu to create new combat styles.
One way it could be possible is if Naruto somehow gains access to the knowledge of the Hiten Mitsurugi - Ryu through some sort of cross - dimensional encounter. Maybe a rift in space - time brings a master of the style to the Naruto universe, and Naruto, being the curious and quick - learning ninja he is, starts to study and adapt it to his own combat style.
Naruto's version of the Hiten Mitsurugi - Ryu could be more chakra - based. He might use his chakra to enhance the speed and power of his sword strikes, similar to how he uses chakra to power up his shadow clones. His sword could also be a unique creation, perhaps made from a special chakra - infused metal that can withstand his powerful attacks and also channel his chakra more effectively.
It can change the power dynamics. For instance, if a minor character masters the Hiten Mitsurugi - Ryu, they might suddenly become a more formidable opponent, changing the course of battles.
Yes, in some fanfics Naruto might know the Hiten Mitsurugi. Fanfic writers often like to cross different elements from various anime or manga. They could create a scenario where Naruto, being a curious and adaptable character, somehow comes across the Hiten Mitsurugi technique and learns about it. This could be part of a story where Naruto travels to different worlds or meets characters from other series.
He could learn it from a crossover character. If there's a character from Rurouni Kenshin in the fanfic, that character might teach Naruto the Hiten Mitsurugi. For instance, if Kenshin himself is in the story, he could see potential in Naruto and decide to pass on his knowledge of this sword technique.
He might learn a time - traveling jutsu. This would be really cool as it could allow him to go back and change certain events in the Naruto world, or gain knowledge from the past to use in the present battles.
One common theme is power. Since the Ryu concept often brings in strong and unique powers, the fanfictions usually explore how these powers are developed and used in the Naruto setting. Another theme is identity. Characters with Ryu elements often have to figure out their place in the world, whether they are accepted or not.