With Sakura, Naruto's usual boisterous attempts to get her attention would be replaced by more silent and poignant gestures. Sakura might start to see a different, more mature side of Naruto as she tries to understand his new situation. And Naruto might become more observant of Sakura's needs without the ability to just shout out his thoughts.
His relationship with Sasuke would be deeply affected. Without being able to verbally challenge Sasuke or express his feelings directly, Naruto would have to rely on his actions even more. Sasuke might initially misinterpret Naruto's silence as weakness or indifference.
His relationship with his old friends like Sasuke would likely become more of an equal partnership. Since they are both highly skilled, they could collaborate on important missions. With Sakura, he might be seen as more of a respected colleague, and she could look up to him in a different way as a Jounin.
His relationship with his friends might change. His friends could be initially worried about the nanites in Naruto. For example, Sakura might try to find a way to remove them, thinking they are harmful. But Naruto would have to convince her that they are a part of him now.
With his friends in Konoha, they might initially be shocked by his new appearance. But then, they would get used to it. Naruto's popularity among the villagers could skyrocket. People who once shunned him might now be more accepting. This could also change his relationship with Iruka sensei. Iruka would be proud of how Naruto has grown not just in terms of power but also in his appearance, and their bond could become even stronger as Naruto becomes a more respected figure in the village.
His relationship with Sasuke might be affected. Naruto might approach Sasuke differently, with new strategies learned from Zetsu. He could be more secretive about his intentions towards Sasuke, which might either make Sasuke more curious or more distrustful. With his friends in Konoha, they might be a bit wary of Naruto at first because of his new training source. But once they see that Naruto is still on their side, they would support him.
His relationship with the Hidden Leaf would be strained. He might see the village as a source of weakness rather than a place to protect. And his friends in the village, like Sasuke and Sakura, would be more like strangers to him. He would not have the same bonds that were formed through growing up in the Leaf.
Naruto's relationship with his sensei, like Kakashi, would change. Kakashi would be both proud and cautious. Proud because Naruto is getting stronger, but cautious as the Shinigami - related training is uncharted territory. His bond with the other villagers would also shift. Some might see him as a protector with new, otherworldly powers, while others might be suspicious of the Shinigami's influence on him. Overall, his relationships would be in a state of flux as he adapts to his new self after the training.
With his friends in Konoha, like Sakura and Kakashi, there would be a major shift. Sakura might initially be conflicted between her loyalty to the village and her friendship with Naruto. Kakashi, being a more experienced shinobi, might understand Naruto's reasons better but still be bound by his duties to the village. Overall, Naruto's departure as a nukenin would create a lot of emotional turmoil among his relationships.
If Naruto is in a female - ruled fanfic, his relationships would shift. With female characters in power, he would have to interact with them differently. For instance, his friendship with Sakura could change as she might have a more authoritative role. And his relationships with female antagonists could also be different as they might be more in line with the female - led power structure in the fanfic.
If Naruto becomes cold, his relationship with Hinata would be severely affected. Hinata, who loves him for his warm heart, might be at a loss. Naruto might start to push her away, not allowing her to get close. His friends from Team 7 might try to bring back the old Naruto, but his coldness would create a rift between them.
In a crossover with One Piece, Naruto's muteness would change his relationship with Luffy. Luffy might be initially confused but would quickly adapt and start communicating in his own unique way with Naruto. Their bond would be more about shared adventures and understanding through actions rather than words.