One common theme is the cross - over of their abilities. Since Naruto has ninja skills and Kenichi is into martial arts, fanfics often explore how they can combine or contrast these skills.
One possible fanfic could be about a crossover where Naruto and Kenichi meet. Maybe Naruto visits the world of Kenichi and they end up training together. Naruto could teach Kenichi some of his ninja techniques, while Kenichi shows Naruto his martial arts skills.
One popular 'kenichi fanfic' could be 'Kenichi's New Adventure' which might explore new martial arts challenges for Kenichi. Another could be 'Kenichi and the Mysterious Ally' where he teams up with an unexpected character. There are also some fanfics that focus on Kenichi's relationships, like 'Kenichi's Growing Bonds' which delves into his friendships and how they evolve over time.
One common theme is adventure. Writers often put them in exciting situations where they have to face challenges together, like exploring a mysterious land or fighting against a powerful enemy.
One possible plot could be that Naruto finds himself in the world of Kenichi and decides to train at the Ryozanpaku dojo. He could bring his unique ninja skills and chakra techniques, which would amaze the masters there. Maybe he'd get into friendly sparring matches with the disciples, teaching them some of his ninja tricks in return for learning their martial arts. This would create a lot of comical and action - packed moments as Naruto's high - energy ninja style clashes with the more traditional martial arts of the Kenichi universe.
In the world of fandom, creativity is highly valued, but it should be within the bounds of propriety. Sexual fanfics are not in line with the values that most fan communities uphold. These communities are often made up of people of all ages and backgrounds, and such inappropriate content has no place in a healthy fan environment.
One common theme is adventure. Since both Kenichi and the world of Katanagatari have elements of action and exploration, fanfics often bring these two together in exciting adventures. Another theme could be self - discovery. The characters may learn more about themselves as they interact with each other from different universes.
Well, I haven't read many 'kenichi x katanagatari fanfics' myself. However, you could also check out Archive of Our Own (AO3). It has a large collection of fan - created works. You might have to dig a bit through the search results, but chances are you'll find some fanfics that suit your taste regarding the kenichi x katanagatari pairing.
A major theme is also the exploration of different cultures within the two fictional universes. The ninja world of Naruto and the martial arts world of Kenichi have their own unique cultures. Fanfic writers often use this to create interesting scenarios. For instance, they might have Kenichi participate in a ninja festival in the Naruto world, or Naruto train in a traditional martial arts dojo in Kenichi's world. This theme of cultural exchange adds depth to the stories.