She could be an undercover agent from a rival village like Sand Village. They might be trying to find out about Konoha's new defense strategies or upcoming ninja training programs.
She might be a member of a secret organization within the Naruto world that is not well - known. Her mission is to make contact with the Hokage to propose an alliance or warn of a greater threat that only her organization is aware of at the moment.
Maybe she's actually a runaway ninja from her own village who's in disguise to seek protection from the Hokage. She has a valuable skill or information that she hopes will convince the Hokage to let her stay. Along the way, she has to deal with the suspicion of the villagers and the ninja guards.
One example could be a fanfiction where Sakura disguises herself as a male ninja to enter a male - only training area. She does this to prove that she can be as strong as the boys. In the story, she has to constantly be on guard not to be discovered, which creates a lot of comical and tense situations.
The theme of breaking gender norms is also quite prevalent. In the Naruto universe, there are certain expectations for male and female ninjas. A girl disguising as a boy challenges those norms. It shows that girls can be just as good in areas that are traditionally male - dominated, like combat or strategic planning. They can prove themselves equal or even better than their male counterparts through the disguise.
Another possibility could be Sakura. Although she had feelings for Sasuke for a long time, in a fan - created scenario, things could have taken a different turn and she could end up in a relationship with Naruto and get pregnant. However, this would be quite a departure from the original plot dynamics.
Sasuke could be an alternative. He has strong ninja skills and a deep understanding of the ninja world. His experiences have made him grow into a very capable person, and his Sharingan gives him an edge in combat and strategic planning.
She could be a kunoichi from a small, unknown village who comes to Konoha on a mission. Naruto, being the friendly and trusting person he is, befriends her. But she has a hidden agenda and uses Naruto's feelings for her own ends, breaking his heart in the process.
The ghost girl could be a long - lost Uzumaki. Since Naruto is an Uzumaki, it would make sense that she is from his clan. Maybe she had some special powers that were lost over time, and Naruto is the key to bringing them back.
Even Naruto himself could be a subject of this 'evil Hokage' concept in fanfiction. Maybe he is possessed by some dark entity or has a major change of heart due to some extreme event. This would completely change his character and turn him into an evil Hokage, which would be a very interesting and unexpected twist.
In this fanfiction, a great plot point could be Naruto's interaction with the male characters as a girl. There could be some unexpected romantic interests that develop. For instance, some of the guys who previously saw her as just a rival might start to see her in a new light. And her struggle to maintain her disguise while still being true to her ninja self would be an overarching and interesting plot thread.
The fanfiction alters Naruto's character development in that she now has to deal with the social norms and expectations for girls in the ninja world. This means she may become more self - aware of her appearance and how she presents herself. Also, her relationships with other characters, especially male ones, will be different. She'll have to navigate new types of interactions, which will shape her character in new ways.