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.
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.
Well, in such a fanfiction, perhaps there's a political conspiracy behind forcing Naruto to be Hokage. Maybe some hidden group wants to control him through the Hokage position. Naruto then has to not only deal with the responsibilities of being Hokage but also uncover the conspiracy. He'd be constantly at odds with the council who forced him into this role, trying to prove that he can do a good job on his own terms.
One possible plot could be that Naruto is somehow transported to a different timeline where he has to fight the Hokage for a misunderstanding. Maybe there's a villain who has manipulated events to make the Hokage think Naruto is a threat. So Naruto has to fight not only to prove his innocence but also to save the village from the real danger that the villain poses.
Maybe Naruto has always idolized the Hokage in secret. He could be studying the ways of past Hokages on his own, trying to learn their leadership skills and jutsu. For example, he might be secretly practicing Minato's Flying Thunder God Technique because he admires his father so much.
The fanfiction could be about Naruto's struggle to adjust to a normal life after being Hokage. He might feel a bit lost without the constant stream of paperwork and decision - making. So, he starts to explore his hobbies, like fishing. Meanwhile, he still has to deal with some remnants of old enemies who are trying to take advantage of his retirement, and he has to use his skills and influence in a different way to protect Konoha.
There could be a focus on Naruto learning new forms of the Rasengan. Hokage Naruto, with his vast experience, could teach Naruto different ways to infuse the Rasengan with other elements more easily. Maybe Naruto would learn how to quickly switch between a Fire - Rasengan and a Wind - Rasengan during combat.
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.
One possible plot could be Naruto dealing with the post - war reconstruction. He might focus on rebuilding the village, strengthening relations with other villages, and also mentoring the new generation of ninjas. For example, he could start new training programs inspired by his own experiences.
In this fanfiction, Naruto might go back to the time when he was a child. He could use his future skills and wisdom to outwit his enemies from that time, like Orochimaru. He could also help his friends, like Sasuke, in a different way. Maybe he could prevent Sasuke from leaving the village in the first place. This would lead to a completely different story arc for both of them and for the whole Konoha village.
One possible plot could be Naruto having to prove himself to the village elders. He might start by implementing new training programs for the younger ninjas, inspired by his own journey. He could also focus on improving relations with other villages, using his charisma and unique perspective as someone who was once an outcast.