He could feel a sense of guilt. Sasuke might think that his actions or their relationship issues pushed Naruto to leave. He may then set out to find Naruto, not only to bring him back but also to resolve their long - standing issues. For example, if there were unspoken words or unresolved fights between them, Sasuke would see this as an opportunity to set things right.
One possibility is that Naruto is on a quest for self - discovery. Leaving the village to find the Sage gives him a chance to be away from the familiar and face new challenges alone. He might encounter different types of enemies and allies during this journey. This could also be a way for him to prove himself not just to the village but also to himself. He wants to show that he can grow and become stronger without always relying on the village's resources.
Naruto might encounter a group of rogue ninjas. At first, they seem like enemies, but as he gets to know them, he realizes they have their own reasons for being outcasts. They could teach Naruto some unorthodox fighting styles that are not taught in the Leaf Village. Also, there could be a mysterious traveler who has knowledge about Naruto's family that even he doesn't know. This traveler could be the key to unlocking some hidden power within Naruto.
In the sasunaru context, perhaps a rift between Sasuke and Naruto makes Naruto feel like he needs to leave to sort out his feelings. He might think that staying in the village constantly reminded of Sasuke and their complicated relationship is too much to bear, so he leaves to find his own path and hopefully reconcile with Sasuke on his own terms.
Well, Naruto could leave the village in a fanfic due to a prophecy. He might believe that leaving is the only way to fulfill a greater destiny that the village can't support. As he leaves, he starts to explore different cultures of the ninja world. He learns about new forms of jutsu and how other villages operate. He could also form a team with outcasts from different villages, and together they strive to change the way the ninja world views things.
Definitely Naruto and Sasuke. Naruto is the one leaving the village, so he's a central figure. Sasuke, given the 'narusasu' aspect, is bound to play a crucial role too. He could be the one Naruto is leaving behind, or he could be the one who follows Naruto out of the village. There might also be other supporting characters from the Naruto universe like Kakashi or Sakura who could be affected by Naruto's departure.
Perhaps Naruto in the Anbu has a personal mission that goes against the village's orders. For example, he might befriend someone from an enemy village who is actually innocent but is being targeted by Konoha. When the village refuses to listen to his pleas, he decides to leave. He'll use his Anbu abilities to protect his new friend and find a new place where they can both be safe, away from the political drama of the ninja villages.
There's also 'Beyond the Village Borders'. It focuses on Naruto's journey outside the village and how Sakura secretly misses him. As the story unfolds, they communicate through letters which gradually deepens their bond.
In this fanfiction, Naruto might be neglected not just by the villagers but also by some of his so - called friends. This heartbreak makes him leave. He then travels to different lands. Along the way, he meets an old hermit who teaches him ancient ninja techniques that are long forgotten in his village. With these new skills, he contemplates whether to return to the village and show them what they missed out on or to start a new life away from the place that has caused him so much pain.
The ninja elders in Konoha could see it as a potential threat. They might worry that Fem Naruto leaving could expose Konoha's secrets or that she could be turned against the village by enemies. So, they would start to take measures to protect Konoha's interests. They could send out spies to keep an eye on her or try to find a way to bring her back. On the other hand, the younger generation of ninjas might be inspired by her courage to break free and seek their own paths outside of the village.