Well, there could be a story where Naruto lands on Earth and is mistaken for a superhero. People see his cool ninja moves and think he's some kind of new, amazing hero. He then has to deal with the fame and also the responsibility that comes with it. He might use his new - found popularity to spread the message of friendship and hard work, just like he did in his own world.
Obviously Naruto himself is the main character. But often, he'll interact with local Earth characters. Sometimes it could be a group of teenagers who befriend him and help him navigate the strange new world. They might learn from Naruto and Naruto will learn from them too.
One possible plot could be Naruto exploring the modern technology on Earth. He'd be amazed by things like cars and phones which are completely different from what he has in his own world. He might use his ninja skills in unexpected ways, like using his speed to compete in track races and becoming a local celebrity.
Naruto would likely be very confused at first. But his determined nature would help him adapt. He'd start by learning basic things like how to use money. Since he's used to a barter system in his world, this would be a new concept. He might also pick up on the local language quickly, as he's always been a fast learner.
One possible scenario could be that all of Naruto's friends are killed in a great battle. He survives but is left alone, haunted by the memories of his lost comrades. He might then wander the world, a solitary figure, with his only company being the memories of the past.
Well, he might join a magic guild. Since Naruto is strong and has his own set of skills like ninjutsu, he could easily adapt to the magic battles in Fiore. Maybe he'd learn some magic too, combining it with his ninja abilities to become an even more formidable fighter.
He might use his ninja skills to survive in Westeros. His ability to move stealthily and his combat skills could make him a formidable figure. He could also form alliances with some of the characters in Westeros, perhaps teaching them some of his ninja techniques in return for knowledge about the land.
Well, he might be completely out of his depth at first. Naruto's ninja skills are cool, but in the DBZ universe with all those super - powered Saiyans and other strong beings. He'd probably try to make friends and learn about the new world. Maybe he'd try to use his Rasengan against a Ki blast, which would be an interesting sight.
In this kind of fanfiction scenario, Naruto could face challenges from future villains who have powers he's not familiar with. However, his own experience and strong will would still be valuable assets. He might also meet descendants of his friends and discover how his actions in the past have influenced the future in ways he never expected. For example, he could find that a village was founded in his honor, or that a new style of ninja training was developed based on his teachings.
Naruto might become bitter. After being alone, he could start to question all the values he once held. He may think that his efforts to protect and connect with others were in vain, which could lead to a cynical view of the world.