Maybe Naruto meets a group of friendly but highly intelligent animals during his trip. These animals have their own form of ninja skills and they teach Naruto how to think like them, which in turn makes him smarter in combat and decision - making.
He could meet an old hermit ninja who imparts his wisdom and knowledge to Naruto. This hermit might have been living in seclusion for years, but seeing Naruto's potential, decides to teach him things not found in normal ninja training.
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.
Naruto might meet some foreign ninjas from far - off lands that have completely different fighting styles. These ninjas could teach him new ways to use his chakra and improve his combat abilities. He may also encounter some mysterious hermits living in the mountains or forests who possess great wisdom and unique jutsu. They could guide him on his journey of self - improvement and give him valuable advice on how to become stronger as a ninja.
He could meet some old enemies who have changed their ways. For instance, some of Orochimaru's former minions might have decided to start anew and cross paths with Naruto. Or perhaps he meets a hermit ninja who has been living in isolation for years and imparts some valuable wisdom to him.
He could meet other sannin. Maybe he stumbles upon Orochimaru who is on some secret mission. This encounter would be full of danger and Naruto would have to use all his skills and wits to survive.
One possible plot could be that Naruto returns from his training trip with new jutsu and a more strategic mind. He starts to outwit his opponents in battles, surprising everyone in the village. For example, he uses his newfound knowledge to defeat a group of rogue ninjas who were causing trouble near Konoha.
Well, in this fanfiction's training trip, Naruto may come across different clans with their own exclusive fighting styles. He could engage in friendly sparring matches with their members, which would not only enhance his combat abilities but also his understanding of different cultures within the ninja world. He might also find some ancient artifacts that hold great power and have to figure out how to use them properly without being corrupted by their power.
In such a fanfiction, Naruto might return to the village with new and powerful jutsu. He could surprise his friends with his enhanced skills. For example, he might be able to create new types of shadow clones or have a better control over his chakra. Maybe he would also have new insights on how to deal with his enemies, like Orochimaru or the Akatsuki.
It could be due to the current situation in the village. There might be threats that required Naruto to stay. Tsunade, as the Hokage, had to consider the overall safety and stability of the village. So, she denied Naruto's request for the training trip to ensure he was available in case of any emergency.
It could be a rogue ninja who has been secretly observing Naruto during his training trip. This ninja, jealous of Naruto's growth, decides to target him and the village he protects. He has some unique and dangerous abilities that even Naruto's new - found power will have a hard time dealing with at first.
Well, Naruto might learn some new and powerful jutsus during the training trip. Maybe he meets some unique characters who teach him special skills or give him valuable advice.