Hinata would be an important character as Naruto's wife. She could support Naruto in his Hokage duties and also play a role in the social aspects of the village. Their children might also be part of the story, representing the new generation.
Obviously, Naruto is one of the main characters as he is the Rokudaime Hokage in this fanfiction. Sasuke could also be a main character, perhaps as Naruto's advisor or someone who helps him deal with external threats. Sakura might be there too, probably as a medic - ninja in the village, helping to treat the injured during any conflicts.
One interesting plotline could be Naruto facing new and unexpected threats to the village as Rokudaime Hokage. He might have to deal with political intrigue within the village as some may not fully accept his leadership at first.
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.
The other Konoha 11 members would likely be involved too. They might be split in their opinions. Some would firmly stand by Naruto, while others might be swayed by the village's reasons for denying him. Hinata, for instance, would probably be one of Naruto's biggest supporters and might even try to fight against the decision in her own way.
Naruto's family would become a symbol of the village. His wife and children would be in the public eye more often. This could mean added security concerns for them. At the same time, Naruto would try to instill in his family the values he wants to see in the village, like hard work and loyalty.
Yes, in some fanfics of 'Rokudaime Hokage', Sasuke could be depicted as a Naruto fan. Fanfic authors often explore different character dynamics, and Sasuke having an admiration for Naruto similar to a fan's view can add an interesting twist to the story.
One interesting plotline could be Naruto's challenges in leading the village as the Rokudaime Hokage. He might face political intrigue from within the village or threats from other hidden villages. Another could be his attempts to reform the ninja system, bringing in new training methods for the younger generation.
Obviously, the 5th Hokage herself. Then there would probably be Naruto, as he is a central character in the Naruto universe. Sakura might also be there, as she is one of Naruto's closest friends. And Kakashi could make an appearance, given his importance in the story. Shikamaru, with his intelligence, could also be involved, perhaps as an advisor to the 5th Hokage.
Obviously, Naruto himself is central. His family like Hinata and Boruto would be very likely to be involved. Sasuke is also a key character as Naruto's friend and ally. Kakashi, being Naruto's former teacher, could also play a role. Shikamaru, as Naruto's advisor, would be important in any political or strategic situations. And then there are the other members of the Konoha 11, like Sakura who could be involved in medical support or combat situations if needed.
Obviously, Naruto himself is the central character. His friends like Sakura and Kakashi are likely to be involved too. They might support Naruto in his new adventures or face challenges alongside him.