Sure, there are likely fanfictions with this premise. Fanfiction thrives on taking established characters and putting them in unexpected situations. If Naruto were Kakashi's older brother, it would completely change the Naruto universe as we know it. It might mean that Naruto would have a different role in Kakashi's life, perhaps being more protective or having a say in his training. Also, it could impact the story arcs that involve Kakashi, as Naruto's presence as an older brother would add a whole new layer of complexity to his decisions and actions.
There are indeed fanfictions with Naruto being Kakashi's brother. Fanfiction writers like to play around with the established characters and relationships in the Naruto series. This particular concept can open up a whole new set of storylines. For instance, it could change the dynamics between Naruto and other characters like Sasuke or Sakura. Also, it might give Naruto a different perspective on the ninja world, as he would be related to someone as respected as Kakashi.
Well, for one, Kakashi's childhood might have been different. Naruto could have been there to support him after his father's death. Also, Naruto might have influenced Kakashi's attitude towards the Sharingan. He could have been more cautious about Kakashi using it, given its toll on the user.
Well, one possible plot could be that Naruto grows up with Kakashi's guidance from the start. Since Kakashi is so skilled, he could train Naruto in more advanced techniques earlier. This might make Naruto a stronger ninja faster. Also, they could have a closer bond than in the original story, and Naruto might be more confident knowing he has a brother like Kakashi.
One major plot point is the adjustment of their relationship. Naruto might initially be shocked or overjoyed to find out Kakashi is his brother. Then they have to figure out how to act around each other. Another plot point could be the impact on their respective goals. Naruto's goal of becoming Hokage might be influenced by having Kakashi as his brother, and Kakashi's role in the village and his own personal missions could also change due to this new family connection.
Another reason could be related to Kakashi's past actions. If there are some secrets or things Kakashi did in the past that come to light and Naruto doesn't like them, he could snap at Kakashi. Naruto has a strong sense of justice and loyalty, so if he feels betrayed or misled by Kakashi, his reaction could be to snap.
One popular 'naruto is kakashi's little brother fanfiction' might be 'The Hidden Bond'. In it, Naruto's relationship with Kakashi as his brother adds a new layer to the story. It shows how Kakashi would be more protective and how Naruto could learn different skills from him in a more family - oriented way.
I recommend "I am the Second Young Master of the Flagwood Family" to you. The main character of this novel, Flagwood Miren, transmigrated to the Naruto World and became the second young master of the Flagwood Family. He is the same age as Kakashi. The plot of this novel also included other Naruto characters, such as Haki Shuogu, Ban, and Bo Fengshui Gate. I hope you like this fairy's recommendation. Muah ~😗
Well, it could strain their relationship. Avoidance usually creates distance, and in this case, Kakashi might feel hurt or confused as to why Naruto is avoiding him.
One possible reason could be that Naruto might be trying to prove his independence. He has grown and wants to show that he can handle things on his own without always relying on Kakashi's guidance.