The author could use internal monologues. Naruto might think to himself about how he doesn't like the feeling of being touched and how it makes him uneasy. This gives the readers an insight into his emotions regarding physical contact.
It might be shown through his reactions. For example, when someone tries to touch him, he may flinch or move away quickly.
In the fanfiction, other characters may notice his dislike. They could comment on it or try to respect his boundaries. This helps to further emphasize Naruto's aversion to being touched within the context of the story.
In a romantic relationship, it would be a major obstacle. His partner would have to be very patient and understanding. They would need to find other ways to show love and closeness, as physical touch is a common part of a romantic relationship. This could potentially slow down the development of a romantic relationship.
Maybe it's related to his sense of independence. Naruto is used to relying on himself and having others touch him might make him feel like his personal space and autonomy are being invaded. He's always been on a journey to prove himself, and being touched could be seen as a form of interference in that self - discovery process.
In many Naruto fanfictions where he is an awakened being, Naruto often has enhanced powers. He might have greater control over his chakra, and his jutsu could be more powerful. For example, his Rasengan could have additional effects like being able to disrupt an enemy's chakra network on a much larger scale.
It could also be related to his jinchuriki status. The Nine - Tails' chakra within him might make him feel that being touched could lead to the unleashing of that power accidentally, and he's afraid of harming others or losing control. So, to avoid any such situations, he's scared of being touched.
Even with his mentors or senseis, his fear can be a problem. They might want to guide him physically in training, like correcting his stance by touching his arm or shoulder. But Naruto's fear could make him resist this kind of guidance, which could slow down his progress in learning new techniques.
It could also be related to his ninja training. He is always on guard and being touched might disrupt his focus or make him feel vulnerable in a dangerous ninja world. He has to be constantly aware of his surroundings, and unexpected touch could be seen as a threat to his safety.
Often, Naruto's loneliness in fanfiction is shown through his solitary moments. He might be sitting alone on the Hokage Rock, looking over the village that doesn't fully accept him. It's a visual way to represent his isolation.
In Naruto fanfiction, the Rinnegan in Naruto is often portrayed in really cool and powerful ways. Some fanfics might give Naruto the ability to use all the Rinnegan powers to their fullest extent right away, like being able to effortlessly summon the Gedo Statue or use the Deva Path powers without any drawbacks. It's a way for writers to explore new storylines and make Naruto even more of a badass than he already was in the original series.
In Naruto fanfiction, the concept of 'Naruto Demon' can be portrayed in various ways. Sometimes, Naruto might be depicted as having some sort of inner demon that he has to struggle with, like a dark side of his chakra or personality. It could also be that a demon is fused with Naruto in the fanfiction's alternate universe. This can lead to new powers and challenges for him as he tries to control or come to terms with this new aspect of himself.
Naruto would probably be his usual enthusiastic self. He'd be eager to take on the role of a cop, seeing it as a new and exciting adventure. His naivete might show when it comes to the more complex aspects of police work, like dealing with political issues within the force.