Kakashi could also be paired with them. His experience as a ninja and his unique Sharingan abilities would be a great asset. He could mentor Naruto and Choji, guiding them through difficult situations and teaching them new jutsu in the process.
Shikamaru is another excellent choice. His intelligence combined with Naruto's determination and Choji's strength would make for a very balanced team. In a fanfiction, they could be solving complex puzzles or devising strategies to outwit their enemies.
Sakura could be a great character to pair with them. She has her medical ninjutsu skills which could come in handy during their adventures. For instance, if they get injured during a battle, she can heal them quickly. Also, her strong - willed personality adds an interesting dynamic to the group.
Another character could be Kakashi. Kakashi's wisdom combined with Byakuya's combat skills and Naruto's determination would make for a really engaging story. Kakashi could study Byakuya's techniques and try to incorporate some of that into Naruto's training, while also trying to understand Byakuya's motives in the Naruto world.
Another good pair could be Kakashi and Eminem. Kakashi is a very laid - back yet highly skilled character. His calm demeanor could contrast well with Eminem's energetic and often angry - inspired lyrics, leading to some unique exchanges and perhaps even Kakashi learning a thing or two from Eminem about expressing emotions.
Naruto himself could be a great character to pair with Magneto. Their different powers and personalities would create an interesting dynamic. Naruto's positive and determined attitude could contrast with Magneto's more serious and sometimes harsh nature. Also, they could learn from each other's combat styles and strategies.
I think Naruto and Kakashi would also work well. Kakashi is already quite intelligent and has a lot of experience. He could be like Holmes, guiding Naruto, who is like a young and eager Watson. Naruto's enthusiasm and his unique ninja skills could add a new dimension to their detective work. For instance, Naruto could use his Rasengan to break through obstacles during their investigations.
I think Ichigo would be a great character to pair with Naruto in Kisuke fanfiction. Since Kisuke has a connection to Ichigo's story, and Ichigo's combat style and determination could match well with Naruto's. They could learn from each other and have some really cool team - up moments.
Naruto and Carly themselves are great to pair as they come from such different worlds and can learn a lot from each other. Their interactions would be really interesting to explore.
Hidan could be a great character to pair with Kushimaru. They are both members of the Akatsuki, and their different personalities would create an interesting dynamic. Hidan's brash and bloodthirsty nature contrasted with Kushimaru's more reserved and calculated style could lead to some exciting storylines.
Kakuzu would be a great character to pair with Hidan in fanfiction. They were partners in the original story and had a very interesting dynamic. Kakuzu was always exasperated with Hidan's wild and unruly ways, which could lead to some humorous and tense situations in a fanfiction.
Sakura could be a great character to pair with Naruto in Flora fanfiction. She could act as a mentor to Flora, teaching her medical ninjutsu while Naruto teaches Flora some of his combat moves. Their combined efforts would make for an interesting dynamic.
I think Mario and Hinata would be an interesting pair. Hinata's shy but strong - willed nature could contrast with Mario's always - positive and heroic attitude. And Mario could help Hinata become more confident in this cross - over scenario. Another good pair could be Toad and Shikamaru. Toad's small but brave self and Shikamaru's intelligence would make for an engaging dynamic.