After the 4th ninja war, there was a period of peace of about 5 years. Naruto was recognized in the shinobi world as the hero of the war, his succession as Hokage was already certain. So he spent these 5 years continuing to climb the ladder, passing the Junin exam in particular, which took him more time than expected, because of the numerous knowledge that the exam requires. He became Junin and then ANBU during the fifth year.
Sasuke, on the other hand, became the common target of all nations, blaming the Uchiha clan for all the wars of the Shinobi world. Thanks to the unwavering support of Naruto and the Hokage, Hatake Kakashi, as well as the Godaime Kazekage, Sabaku no Gaara, Sasuke was not killed but only imprisoned. He stayed 3 years in Konoha prison, officially in the most secure room under 24 hour surveillance. Unofficially, he lived with Naruto during these three years, only going out in disguise so as not to arouse suspicion.He left the apartment several times, touring the nations and trying to find a new meaning to his life, and not wanting to stay in Konoha, his grudge still too great.
Then, the Tsuchikage and the Raikage, the two Kage most fiercely opposed to his release and wishing him dead, were replaced by new Kages. They agreed to allow the release of Uchiha Sasuke in exchange for one thing: that he will be put on a seal that could kill him at a distance and another that would prevent him from using his chakra. This in order that he is perfectly under control and that he is at the service of the shinobi world. And also, so that he is not another powerful shinobi in the village of Konoha, because it destabilizes the balance of power between the big nations, the fire nation having become extremely powerful since the fourth ninja war, because nobody dared to attack it, because it was protected by the "war hero" Uzumaki Naruto. The other nations, meanwhile, continued to fight each other to increase their power and eventually allied themselves against Konoha over the years.
This led to disputes between the nations, with the Hokage refusing to enslave his former apprentice. The exchanges became more and more tense, and two blocks began to form: Konoha and Suna on one side, Kumo, Kiri and Iwa on the other. Kiri having remained neutral until then, the Mizukage decided to ally with the villages of lightning and rocks.
Faced with the rising tensions, Naruto intervened and tried to calm down the tensions during a conference with the 5 Kages. However, the new Raikage and Tsuchikage remained in their positions and he found himself in a deadlock.
These last years having changed him, following the discovery of some secrets of Konoha and other villages once he became ANBU, his dream of changing the shinobi world and of being Hokage seemed to him more and more childish. These last years spent with Sasuke allowed him to understand some things, especially the fact that the big nations such as the Nation of Fire, had totally crushed and enslaved other smaller nations to reach their end. And to be a Hokage meant to be in the service of the Fire Nation, something he found more and more absurd.
So, as tensions grew between the nations and another war seemed to be coming, he made his decision. He wanted to change the shinobi world and being Hokage might not be the best solution after all. He began to imagine his life as a Nanadaime, working hard, probably married to Hinata, having children with her too, not by choice but by obligation. He imagined the life that awaited him, serving the Fire Nation, having to fulfill his role and having too much responsibility that would prevent him from doing what he wanted to do, not being able to oppose injustice head on for fear of too many political repercussions. No, this was not the life he wanted. In the last few years, he had been able to talk with Sasuke, their relationship having taken on a new aspect. He wanted to be with him everyday of this life, now that they have acknowledged each other love, cause that’s what their bond really was since the beginning, he will not live without him. His happiness depending on him, they will change the shinobi world together, for real. By revealing the great injustices of this world, like the massacre of the Uchiha clan among others. And by preventing that from happening again, being both the most powerful shinobi in this world, he could change things for sure.
So, as the conference of the 5 Kages came to an end, threats having been made and war was about to be unleashed, they arrived. Naruto was still wearing his headband, but this time around his neck, meaning that he did not officially belong to Konoha anymore, but his heart did. They threatened the five kages that if a war was declared, they would have to face them. They would never let another war happen again.
So they became the common enemy of the 3 kages, Konoha and Suna did not speak out, Gaara and Kakashi not really knowing how to react at the moment, and not wanting to take a position for fear of diplomatic repercussions. But after the announcement of the two shinobis, they were at first very surprised. But they couldn't help smiling. Seeing these two, their looks more determined than ever, they began to hope that in the end, yes, maybe it was the right choice. People from all over the world, including shinobi and citizens, admired them and they became heroes of peace. For fear of confrontation, war was not declared and the world was at peace for many years thanks to those two. They were called 太陽と月：平和の守護者 Taiyō to tsuki: Heiwa no gādian "The Sun and the Moon: Guardian of the peace