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.
Obviously Naruto himself. Since he is the one going to the past, he would be the central character. His younger self would also be important as he would interact with his future self.
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.
Perhaps the plot of this 'future Naruto goes to the past fanfic' is centered around Naruto's desire to reunite with his parents. In the future, he realizes that by going back in time, he could meet them when they were alive. So, he travels to the past. Once there, he not only gets to meet his parents but also tries to change some things in the past that would lead to a better future for the entire Hidden Leaf Village. He might use his knowledge of future threats to prepare the village earlier. He could also try to influence his younger self's relationships with other characters, like Sasuke. Maybe he tries to prevent Sasuke from leaving the village in the first place by showing him a vision of the future if he does leave. This would be a very emotional and action - packed plot, full of opportunities for character development and exciting twists.
He would probably use his leadership skills. Naruto has grown into a great leader as Hokage. In the past, he could quickly assess situations and lead others, whether it's in a battle or in village - building activities.
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.
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.
Well, in a 'Hokage Naruto guards Hogwarts' fanfiction, perhaps Naruto is brought to Hogwarts because Voldemort's return has created a need for a different kind of protector. Naruto, with his experience fighting powerful foes in his own world, could start by assessing the security of Hogwarts. He'd be amazed by the magic there, but soon adapt and use his chakra - based abilities along with some Hogwarts magic he picks up to keep the school safe. For example, he could use his Rasengan to fend off Dementors, as it's a powerful and concentrated form of energy.