Ruby Rose for sure. They both have a strong sense of justice and a desire to protect others. Naruto would be intrigued by Ruby's scythe and her use of Dust. And Ruby would be interested in Naruto's ninja tools and jutsu.
Yang Xiao Long would also be a likely character. Yang is strong - willed and Naruto's boisterous nature would mesh well with hers. They could have some friendly sparring matches where Naruto shows off his taijutsu and Yang shows off her brawler style. Plus, Yang could teach Naruto about the different types of Grimm.
Naruto and Ruby are very likely to interact. Ruby is the main character in RWBY, and Naruto being the central figure in his own story, their paths would surely cross. Ruby's enthusiasm for combat and her leadership qualities could make for an interesting dynamic with Naruto's determination and his own brand of leadership. Also, Weiss could interact with Naruto. Given Weiss's strict upbringing and her proficiency in combat, her reaction to Naruto's unorthodox ninja techniques would be fascinating.
Iron Man is another candidate. Tony Stark's technology and Naruto's ninja techniques could be a great contrast. They could learn from each other. Stark might be interested in Naruto's chakra - based powers and try to replicate them in some way, while Naruto could be amazed by Stark's high - tech gadgets.
I think Naruto and Optimus Prime would be likely to interact. Naruto is the main character in his world, always looking for ways to protect his friends and village. Optimus Prime is the noble leader of the Autobots. Their leadership qualities and sense of justice would make them natural allies. They could share their experiences and strategies in fighting against evil.
I think Sakura from Naruto and Stella from Winx could interact a lot. Sakura is a strong - willed and intelligent kunoichi, and Stella is a confident and powerful fairy. They could have some really interesting conversations about their respective worlds, like comparing the medical ninjutsu in Naruto's world to the healing magic in the Winx world. And they might also get into some friendly rivalries while training together.
In my opinion, Kakashi from Naruto would be an interesting character to interact with Tuff Puppy. Kakashi's calm and collected nature combined with his powerful ninja skills could create some cool scenes when paired with Tuff's more energetic and comical style. And of course, Shikamaru's intelligence would make for an interesting interaction with any of the characters in Tuff Puppy's world who need some smart thinking to solve a problem.
Naruto and Star - Lord would be likely to interact. Naruto's friendly and outgoing nature would draw him to Star - Lord's charisma. They both have a sense of adventure and a desire to protect their own groups. Naruto might be curious about Star - Lord's blasters and spaceship, while Star - Lord could be interested in Naruto's ninjutsu.
Definitely Naruto and the Punisher first. Naruto would be intrigued by the Punisher's methods and would try to understand his motives. It's also possible that Sakura could interact with the Punisher. She's a strong - willed character, and she might try to either stop the Punisher if she thinks his actions are too extreme or help him if she sees the good in his goals. And Jiraiya might also be a character who could cross paths with the Punisher. Jiraiya's worldliness and his own sense of right and wrong could lead to some deep discussions between them.
Definitely the Teen Titans. Robin would be interested in Naruto's strategic mind and combat skills. Starfire might be fascinated by Naruto's unique culture. Beast Boy and Naruto could bond over their fun - loving natures. And Cyborg would be intrigued by Naruto's chakra - based abilities compared to his technological ones.
He would likely interact with the Dragonborn. They could have an interesting exchange of skills, with Naruto showing off his Rasengan and the Dragonborn demonstrating shouts. He might also meet the various Jarls in the different holds, trying to understand their leadership styles which are different from the Hokage in Konoha.
Sasuke and Magneto. Both are complex characters with a bit of a dark side. They could either become enemies as their goals might clash. Sasuke is on a journey to gain power for revenge, and Magneto wants to protect mutants but sometimes uses extreme methods. Or they could form an unlikely alliance, learning from each other's determination and power - seeking motives.