Obviously, Naruto is one of the main characters as the title implies he's the Hokage after Pein. Sakura could also be a main character as she is one of Naruto's closest friends and a strong ninja in her own right. Kakashi might also play an important role, as he has always been Naruto's mentor in a way.
It could be the First Hokage, Hashirama. Naruto would be amazed by his powerful Wood - Style jutsu and his ability to create the village. He could learn about the original ideals behind the Hidden Leaf from Hashirama.
Shikamaru is another possibility. He is known for his strategic mind. As Hokage, he could use his intelligence to make wise decisions for the village. He may not have the brute strength of Naruto or Sasuke, but his ability to plan and analyze situations would be invaluable in leading Konoha.
It could be some rogue ninjas who were against the peace treaties after the war. They might form a group and try to disrupt the newly - established peace in the ninja world.
His friends like Sakura and Shikamaru would surely support him. Sakura, with her medical skills, could be an important part of his regime, providing healthcare for the ninjas. Shikamaru, being intelligent, could offer strategic advice. Also, the younger generation of ninjas who have been inspired by Naruto would be his strong supporters, as they believe in his leadership and the new direction he could take the village in.
Naruto would probably first assess the damage to the village. He would send out teams to check on the injured and start the process of getting the necessary supplies for the repairs. Then, he would call a meeting with the village council to discuss security measures to prevent future attacks like Pain's. He'd want to make sure that the village is well - defended and that they have a proper warning system in place.
Sasuke could also be a possibility for the 6th Hokage in the fanfic. He has grown stronger over the years and his unique perspective on the ninja world could bring new ideas to the leadership of the Hidden Leaf. He might start off as a controversial choice but prove himself through his actions in protecting the village and making tough decisions.
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.
Another aspect could be Naruto's relationship with the other villages. After Madara, there might be a power shift in the ninja world. As Hokage, Naruto would work towards strengthening the bonds between the villages. He could initiate more joint ninja training programs and diplomatic meetings to ensure long - term peace.
In the 'Naruto Hokage after Pein' fanfiction, Naruto may face challenges in uniting the different clans. After the destruction caused by Pain, there would be a lot of mistrust and internal conflicts. He would have to use his new - found respect as a hero to bring everyone together and work towards a better future for Konoha. He might also start training a new generation of shinobi with a different philosophy, one that focuses more on peace and cooperation rather than just power.