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.
Well, it could be that Naruto is secretly the Hokage in an alternate reality within the fanfiction. He might be leading the village in disguise, using his knowledge of the village and its people to make important decisions. He keeps it a secret to protect the village from potential threats that might target him specifically if they knew he was the Hokage.
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.
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.
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.
One possibility could be that Naruto has been poisoned by a new and unknown enemy. This poison is slowly eating away at his life force, and he's trying to hide it from his friends and family so as not to worry them. He might be secretly seeking a cure while still fulfilling his duties as Hokage.
One possible plot could be that Naruto faked his death to go undercover in a powerful and evil organization. He pretends to be a new recruit while secretly gathering information to take the organization down from the inside.
Perhaps Naruto has developed a special chakra - based concealment technique. This technique would not only hide his physical identity but also any chakra signatures or auras associated with the Hokage position. He might use it when he is out and about in the village, so that even the most perceptive ninja wouldn't suspect that he is the Hokage.
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.
In a fanfiction, if Naruto and Itachi were both involved in the Hokage scenario, Itachi could be resurrected through some means and Naruto, already a respected figure in the village, would propose Itachi as a candidate for Hokage. Itachi would initially be hesitant but Naruto's persuasion and the villagers' need for a different kind of leadership would make him accept. His time as Hokage would involve him training a new generation of shinobi in not just combat but also in understanding the importance of sacrifice and loyalty, with Naruto as his right - hand man, guiding him on how to interact with the more jovial and carefree side of the village life.