Obviously Naruto himself would be the central character. His friends like Sasuke and Sakura would also be involved. Iruka - sensei would play an important role as Naruto's teacher at the academy again. And characters like Kakashi might also make an appearance, perhaps to give Naruto some special training or advice based on his 'second chance' at the academy.
The village elders are very likely to be involved. They often have a say in the big decisions in Konoha. They might be the ones who decide that Naruto must return for the safety or the benefit of the village. Tsunade could also be a part of it. If she's still in charge, she might be in a difficult position of having to order Naruto back or deal with the consequences of his forced return.
Sakura would likely be involved. She might be one of the first to realize the village made a mistake in banishing Naruto. Kakashi too, as he has always been a mentor figure to Naruto. He could be torn between his loyalty to the village and his belief in Naruto. Sasuke could also play a role. Maybe he hears about Naruto's banishment while on his own journey and decides to help bring him back when he realizes Naruto's importance to the village and to himself.
Obviously, Naruto himself is the main character as he is the one sent back in time. Sasuke is also often involved as Naruto's relationship with him is a central part of the Naruto story. Kakashi could be involved too, as Naruto might seek his help or try to influence his training methods. Also, the various Hokages might be important characters as Naruto could interact with them in the past to change the course of events.
There could be new characters specific to the village where he becomes Kamikage. For example, some powerful shinobi clans within that village. Their leaders would be important as they could be Naruto's allies or opponents. Also, the previous Kamikage's advisors might still be around and play a role in guiding or challenging Naruto. Maybe an old sage - like figure who has deep knowledge of the village's secrets and helps Naruto understand and respect the village's heritage.
Sakura could also be a character in these types of fanfictions. Since she had feelings for Sasuke for a long time, some fanfiction writers might come up with a plot where she cheats on Naruto (if they were in a relationship in the fanfic) because of unresolved feelings for Sasuke or some other factor like a misunderstanding with Naruto.
Obviously, Naruto himself is the main character in this situation. His friends like Sasuke and Sakura are very likely to be involved. They would be the ones taking care of him, trying to figure out how to turn him back to normal. Kakashi Sensei would also probably be there, guiding them and trying to keep Naruto safe.
Obviously Naruto himself is the central character as it's about his hibernation. His friends like Sasuke and Sakura are also likely to be involved. They would probably be the ones most concerned about his condition and try to figure out what happened.
Obviously Naruto himself would be the central character. Then, characters like Iruka Sensei could still be involved as he was one of the first to notice Naruto's potential in the original story. Also, Sasuke might be there as Naruto's rival. Even the Hokage, whether it's the Third Hokage at first or others later, would likely play a role in guiding or at least observing this unique Naruto.
The villains in the Naruto universe could also play a role. Maybe the one who turned Naruto into a fox was an enemy seeking revenge or trying to gain some advantage. Orochimaru, for example, could be behind it, hoping to use Naruto's new form for his own evil experiments. And then Naruto, in his fox form, would have to fight against Orochimaru's minions to protect himself and his friends.
Naruto himself could be a victim of family betrayal. His father Minato or mother Kushina might be involved in some alternate - universe plot where they turn against him for some dark reason. Sasuke's family is also a likely candidate. Itachi's actions could be re - imagined in a way where his real motives are more about betrayal of the Uchiha family rather than protecting it. And Hinata's family might be involved too, like if Neji, before his death, was made to betray the Hyuga family in some fan - created scenario.