Well, in the vast world of fanfiction, it's very possible. Some writers enjoy mixing different fictional universes and creating new family dynamics within them. If Naruto were Moka's older brother in a fanfiction, it could bring about a whole new set of adventures. For example, Naruto's ninja skills and Moka's vampire powers could combine in interesting ways to face various threats. But to actually find such a fanfiction, you should start by looking for crossovers between the Naruto and Rosario + Vampire fandoms on major fanfiction platforms.
One unique aspect could be the combination of their powers. Naruto has his ninja abilities like the Rasengan, and Moka might have her vampire - like powers. When they team up, they could create some really cool and unexpected combat strategies. Another aspect is their different personalities. Naruto is loud and outgoing, while Moka can be more reserved in some ways. Their relationship could be about how they balance each other out.
It would probably be full of action. Naruto's combat skills and his never - give - up attitude would blend with Moka's vampire abilities. They might go on adventures together, fighting off enemies that threaten their world or family. Maybe Naruto would teach Moka some of his ninja techniques.
The development of their relationship could be really interesting. At the beginning, Naruto might be a bit confused about having a new sister in Moka. Moka, on the other hand, could be hesitant to accept Naruto as her brother. However, as they spend more time together, they start to rely on each other. They might go on adventures together, facing all kinds of challenges. Through these experiences, they gradually build a deep and loving brother - sister relationship.
Naruto in Moka's body would find it challenging to maintain his usual exuberance. His natural inclination to jump into action would be curbed as he has to adjust to Moka's more ladylike ways. He might become more perceptive of others' emotions, as Moka's character may be more in tune with such things. Moka in Naruto's body would embrace his can - do spirit. She would become more competitive and would be eager to prove herself in the ninja world. Her personality would transform from the somewhat mysterious and alluring one to a more upfront and action - oriented one, much like Naruto's.
One idea could be a crossover adventure where Naruto and Moka find themselves in a strange new world together. They have to combine their unique abilities, Naruto's ninja skills and Moka's vampire powers, to survive and find a way back home.
Inner Moka is also likely to be in these fanfictions. Her more aggressive and powerful side compared to outer Moka can create different scenarios. For example, she might be initially hostile to Naruto but then gradually warm up to him as she sees his good qualities.
Communication might be a big issue. Naruto comes from a world where people communicate in a certain way, and Moka is from a different, more supernatural - oriented culture. They may misunderstand each other's intentions or not be able to fully convey their thoughts. Also, if they are in a world that is not familiar to both of them, they would have to adapt quickly to the new environment while also dealing with their own personal differences.
Naruto might be initially confused by Inner Moka Lemon's powers and appearance. But his friendly nature would make him quickly try to befriend her. He could ask her a lot of questions about her world and abilities.
Yes, there are likely some interesting 'Naruto' and 'Moka Lemon' fanfictions out there. You can start by looking on popular fanfiction websites like FanFiction.net or Archive of Our Own. Just search for the relevant tags, and you might find some unique stories that combine elements from both.