He could interact with Mei Terumi, the Mizukage. She might be initially cautious of Naruto but then see his potential and work with him. Also, Chojuro, as he is one of the important ninjas in Kiri. They could train together or go on missions side by side.
There's also Killer Bee. Since he has a connection to the outside world and is a powerful ninja. Naruto and he could cross paths in Kiri. They might even have some rap battles or just share their ninja experiences. Another character could be Zabuza. Even though he's dead in the original story, in a fanfic, Naruto could somehow encounter his spirit or a young Zabuza - like character and learn some of his swordsmanship skills.
He could meet Mei Terumi. She is a powerful and important figure in Kiri. Naruto might have some interesting interactions with her, either as an ally or having some initial misunderstandings with her. Another character could be Chojuro. He's a kind - hearted ninja, and he might be one of the first to welcome Naruto in Kiri.
Tsunade would definitely be one. As the most renowned medical ninja in the village, she could either be Naruto's mentor or a colleague. They could exchange medical knowledge and experiences.
Naruto might interact with Eostia's warriors. They could train together, Naruto showing them his ninja combat skills and them teaching him about Eostia - style combat. There could also be some mysterious characters in Eostia, like an old hermit who has some knowledge about Naruto's sudden appearance in their world and could guide him on his journey in Eostia.
In a crossover with the Attack on Titan world, characters like Eren could interact with Naruto. Eren, with his strong will to fight for freedom, could learn from Naruto's experience as a father and a hero. Levi might also be interested in Naruto's combat skills and how he trains his child in the ways of the ninja.
Well, Kakashi could play an important role. Since he was Naruto's mentor, he would be very curious about Naruto's sudden change to a nobody. He might secretly investigate what caused this. Shikamaru could also interact with Naruto. Shikamaru is smart and observant. He might notice some small details about Naruto that others miss, and try to figure out the mystery behind Naruto becoming a nobody. Also, Rock Lee could be in the story. Lee might see Naruto as a new opportunity to spread his 'youth' spirit, not knowing Naruto's past.
Ruby Rose for sure. She's the main character in Remnant and Naruto would likely be drawn to her energy and determination. He could also interact with Weiss Schnee. Naruto might be interested in her family's power and wealth, and Weiss could be curious about Naruto's strange abilities. Another one could be Blake Belladonna. Given her past and her more reserved nature, Naruto might try to befriend her and help her open up more.
He could also interact with the scientists on Pandora. They might be interested in Naruto's abilities and study him. Naruto could in turn learn about their technology, which is so different from what he has in his own world. He might even help them solve some problems they have on Pandora using his ninja wisdom.
Well, perhaps in this fanfiction, Naruto goes to Kiri to escape some sort of danger in Konoha. Once in Kiri, he finds himself in the middle of the village's internal power struggles. He uses his skills and determination to try and bring peace to the village, while also dealing with the fact that he's an outsider. He might even start to train some of the younger ninjas in Kiri, sharing his unique ninja way.
He could interact with Ichigo from Bleach. Since Naruto is in a godlike state, their encounter would be really intense. Ichigo might be both in awe and on guard against Naruto's overwhelming power.