Perhaps he would journey to the Hidden Cloud Village. There he could meet new people and learn different techniques. He might also try to bridge the gap between Konoha and the Cloud Village, starting from outside Konoha's boundaries. This would be a way for him to still work towards peace on a larger scale, but away from the restrictions he felt in Konoha.
On a more positive note, it could inspire some young ninja to step up. They would see Naruto's departure as a challenge to prove themselves and fill the gap he left. His leaving could also make Konoha re - evaluate its relationship with its ninja and how to keep them satisfied and in the village.
Well, Naruto might leave Konoha because of the political unrest within the village. He may feel that his ideals are not being supported by the current leadership. For example, if they are more focused on power and control rather than the well - being of everyone. And perhaps he's just tired of the never - ending cycle of conflict that always seems to involve Konoha, and he wants to find his own path away from it all.
The relationship between Konoha and the Uzumaki clan might be further strained. With Kushina leaving, Konoha would lose an important link to the Uzumaki. And other Uzumaki members might see this as a sign that Konoha is not a safe place for them.
One possible reason could be for Naruto's safety. Maybe she has to go on a dangerous mission and believes Konoha is the safest place for him. Another reason might be that she is forced by some powerful enemies who threaten Naruto's life if she doesn't leave him in Konoha.
One possible reason could be that Naruto discovers some dark secrets about Konoha that shatter his idealized view of the village. Maybe he finds out that the village elders were involved in unethical practices, like using shinobi for immoral experiments. This would make him lose faith in Konoha and decide to leave.
Maybe Naruto decides to leave Konoha for a while in the fanfiction. He might feel that the village has let him down in some ways and needs to find himself outside of it.
Another reason could be that he witnesses corruption or unfairness within the village leadership. If he sees that the system is rigged against certain groups, including himself or his friends, he could grow to hate Konoha and decide to leave.
Konoha would initially be in shock. Naruto is a hero to many in the village, and his sudden departure with Itachi, who was once considered a traitor, would cause a lot of unrest. The villagers might start to question the leadership of the village, wondering why Naruto left and if there was something they could have done to prevent it.
Well, Naruto might first confide in his closest friends like Sasuke or Sakura. They could either support his decision to break away from Konoha's norm or try to convince him to stay. If he leaves, he could encounter new enemies or allies in different lands. His skills and reputation would precede him, but he would be a sort of outcast from his own village.
Well, he could encounter new allies and enemies in different villages and face all kinds of challenges on his own journey.