He could learn advanced elemental control. For instance, in some fanfictions, Naruto might master combining different chakra natures in unique ways, like fusing wind and lightning chakra to create a new type of attack. This would give him an edge in combat.
Another skill he could pick up is stealth. Konoha's training might not have focused enough on this aspect for Naruto. While training away, he could encounter situations or mentors that teach him how to move silently, hide his chakra signature better, and become a more elusive opponent. This would be a great addition to his existing combat skills and make him a more well - rounded ninja.
One skill Naruto could pick up is better chakra control for physical attacks. Gai may show Naruto how to focus his chakra more precisely in his limbs when doing taijutsu. This would make his attacks more powerful. Also, Naruto might learn some stealth techniques from Gai. Gai could teach Naruto how to move quietly and quickly, which is very useful in the Chunin Exams where surprise attacks can be a big advantage.
One reason could be that he feels misunderstood by the villagers. Despite all he has done for Konoha, some still hold grudges or are afraid of his power. Another might be that he wants to explore the world on his own terms, away from the responsibilities and restrictions of Konoha. Maybe he also feels a sense of loneliness there, as he has lost many important people and the village constantly reminds him of those losses.
Another reason could be for the sake of protecting the village. Maybe he discovers some sort of threat that he believes he can only face by leaving Konoha. He doesn't want the village to be in danger because of him, so he runs away to draw the danger away from Konoha.
One possible reason could be that he felt misunderstood. In the village, Naruto was often ostracized despite his good intentions. Maybe he got tired of trying to prove himself and just ran away. For example, when the villagers still saw him as the nine - tailed fox rather than Naruto, it might have pushed him to leave.
It would create a sense of panic. Naruto is a very important figure in Konoha. His strength has been crucial in protecting the village. Without him, the villagers would fear attacks from other villages or threats from the Akatsuki. For instance, if the Akatsuki knew Naruto had left Konoha, they would likely see it as an opportunity to capture him more easily.
In fanfiction, Naruto's life away from Konoha could be full of self - discovery. He might meet new and strange people who don't know about his past in Konoha. He could learn different fighting styles and develop his skills in unique ways, without the constraints of Konoha's rules and expectations.
One possible consequence could be that Naruto grows up away from the influence of Konoha's shinobi culture. He might develop a different set of values and skills. For example, without the guidance of Iruka and Kakashi, his understanding of ninjutsu and teamwork could be very different. Also, his relationships with characters like Sasuke and Sakura would be greatly affected. Maybe he wouldn't have the same rivalry with Sasuke, and his bond with Sakura might not even form.
One possible reason could be feeling ostracized. In the Naruto world, being different is often not easily accepted. As a female Naruto, she might face even more scrutiny and prejudice. Maybe she's tired of the constant expectations and the way she's treated in Konoha, so she decides to run away to find a place where she can be herself.
In the fanfiction's training trip, Naruto may encounter some spiritual beings. These beings could be related to the origin of chakra or some long - forgotten ninja legends. Interacting with them would be a very different experience for Naruto. He would have to use not only his physical skills but also his wits and understanding of the ninja world's deeper mysteries to communicate with them. This could lead to a major transformation in his ninja journey, as he delves deeper into the spiritual side of the ninja arts.
His departure would definitely put a strain on his relationships. His close friends like Sasuke, if he is back in Konoha at that time, would have mixed feelings. They might worry about Naruto but also be a bit angry that he left without consulting them. Naruto's younger friends like Boruto would be confused and miss him a great deal, and this could lead to some distance in their relationships.