It could still be Naruto himself. Since he's the central character in the original series, many fanfics would likely continue to build on his story.
Sasuke is also a very likely main character in 'the new naruto fanfic'. His complex relationship with Naruto and his own journey of redemption or power - seeking make him a prime candidate. Additionally, new original characters created by the fanfic author might also take on main character status. They could be students of the original characters, or perhaps mysterious strangers with new powers and motives that drive the story forward.
Well, obviously Naruto himself would be the main character. There could also be his friends like Sasuke and Sakura, who might be involved in the interactions between the two Narutos. Maybe they are confused at first by seeing two Narutos, but then they help them figure out what's going on.
Obviously, Naruto would be the main character. Since it's about him being the new Kyuubi. And his friends like Sasuke, Sakura, Kakashi would also be important characters. They would likely be involved in how they react to Naruto's new state and how they support or oppose him.
Naruto himself is very likely to be one of the main characters. After all, he is the central figure of the Naruto franchise.
Obviously, Naruto himself would be the main character. Since it's about him growing tails, he's at the center of it all. The Nine - Tails would also play a crucial role. It's the source of his tail growth. And his friends like Sasuke and Sakura are likely to be important too. They'll probably be involved in Naruto's journey and how he deals with his new situation.
Most likely Naruto himself. Since it's in the Naruto universe, he's often the central figure. His friends like Sasuke, Sakura, and Kakashi could also be main characters as they usually accompany Naruto on his adventures.
Obviously Naruto is one of the main characters since it's about him watching the future. Sasuke would also likely be a key character, given their long - standing relationship. And Kakashi, as Naruto's former teacher, could play an important role too.
From the Tsukune side, Tsukune would be there as the character being bashed. His friends from his own story might also make an appearance, but mainly to be overshadowed by the Naruto characters. For example, Moka could be in it, but the focus would be on how Naruto characters are better in various aspects compared to her and Tsukune.
Obviously, Naruto and Inoichi are the main characters. Naruto is the one being adopted, and Inoichi is the one doing the adopting.
Obviously, Naruto and Tenzo would be the main characters. Naruto, as the one being trained, is the protagonist of the Naruto series. And Tenzo, with his unique skills, is the trainer in this fanfic.
Most likely Naruto will be the central character. Alongside him, we can expect to see his usual companions. Sakura could be there, perhaps providing some medical support or getting involved in a beach - related mystery. Sasuke might be there too, either as a friend or with some ulterior motives. And Kakashi could be there to guide the young ninjas, especially if there are any dangerous situations or training opportunities on the beach.