Since it's a Naruto - based fanfiction, Naruto himself is likely to be one of the main characters. He's the protagonist of the original series, so he'll probably play a central role in this fanfic too. Sasuke might also be a main character as he has a significant relationship with Naruto.
The main characters in 'naruto is secretly famous fanfiction' are likely to include Naruto. Given the nature of Naruto's story, characters like Jiraiya could also be main characters. Jiraiya was Naruto's mentor and had a major impact on his growth. Additionally, Hinata might be a main character, especially if the fanfiction focuses on Naruto's relationships and her love for Naruto was a big part of the original story.
Well, Naruto is obviously one of the main characters since it's about Naruto secretly being a girl. And Sasuke would also be a key character as Naruto's relationship with him is a significant part of the Naruto story in general.
Sasuke would probably interact differently. As a girl, Naruto might be more of an enigma to him. He could be more protective or more conflicted in his feelings towards her. Instead of just seeing her as a rival, there could be a romantic undertone in their interactions.
Perhaps an old enemy of the Sannin resurfaces. This antagonist could see Naruto's attempts to follow in the Sannin's footsteps as a threat. They might target Naruto to get revenge on the Sannin or to prevent a new powerful force from emerging in the ninja world. For example, if there were a group that was once defeated by the combined efforts of the Sannin, they could try to stop Naruto before he becomes as strong as the Sannin were together.
It could be someone who wants to expose Naruto's secret. Maybe a rogue ninja who wants to use this information to create chaos in the village by making the villagers doubt Naruto's intentions.
I don't know who the author is. There's no information given to determine that.
Well, one interesting aspect could be the unique interpretations of the Naruto characters. Maybe it gives a different perspective on their relationships, like exploring a hidden friendship between Naruto and a minor character. Another aspect could be the new storylines it creates that are not in the original manga or anime. For example, it might have Naruto involved in a secret mission that was never mentioned before.
It could be someone like Freddie Mercury. His flamboyant stage presence and amazing vocal range would surely attract Hermione. She might secretly listen to Queen's music in the Gryffindor common room when no one is around.
Maybe it's a powerful enemy from outside the village who has infiltrated the bingo book system. They see Naruto as a major threat to their plans and so secretly added him to the book, so they can send their minions to take him out without raising too much suspicion.
He could secretly marry Hinata. In the original series, they have a connection, so in fanfiction, it could be a scenario where they elope or have a secret ceremony for some reason, like to avoid political interference in their relationship.
Well, obviously Naruto himself is the central character. Sasuke is often included as his rival. Their relationship in these fanfics can be complex, with Sasuke either being suspicious of Naruto's new - found strength or being inspired by it. Sakura might also be there, trying to figure out what's going on with Naruto and how he got so strong all of a sudden.