One reason could be Naruto's power. In the Naruto universe, Naruto has great power, and both Itachi and Sasuke might see Naruto as a key to achieving certain goals. Itachi might want to protect Naruto because he sees Naruto as a force for good in the future of the ninja world. Sasuke, on the other hand, may view Naruto as a rival in terms of power and influence, and in fanfiction, this could lead to a fight between them over Naruto.
Their relationship could be developed through a series of flashbacks. For instance, Itachi could recall moments from Naruto's childhood that he observed while in the ANBU. These memories could make him see Naruto in a new light. Meanwhile, Naruto could learn about Itachi's past and the sacrifices he made. This exchange of knowledge could build a bond between them based on empathy and respect. In addition, they could train together in secret, with Itachi teaching Naruto some of his ANBU skills, which would also strengthen their relationship.
Naruto would adapt to Itachi's life in several ways. Socially, he'd have to get used to Itachi's connections and rivalries. For instance, his relationship with Kisame would be different as Naruto. He might try to influence Kisame in a more positive way. Emotionally, he'd have to deal with Itachi's internal struggles. Itachi had a lot of guilt and secrets, and Naruto would have to either come to terms with them or find a way to resolve them. And in terms of combat, he'd practice Itachi's signature moves over and over to make sure he could use them effectively in battle.
They could develop a mentor - mentee relationship. Itachi uses his knowledge of the Sharingan to teach Naruto new combat techniques. As they train together, they bond over their shared experiences of loss and their desire to protect the people they care about. Naruto might also help Itachi come to terms with his past actions and find some peace within himself.
The fight would be intense. Itachi would start by using his Sharingan to analyze the enemy's movements and look for weaknesses. His genjutsu would be his first line of attack, trying to trap the enemy in an illusion. Kisame, on the other hand, would rush in with his Samehada, slashing at the enemy with its sharp teeth. The new enemy might counter with some powerful long - range attacks, forcing Itachi and Kisame to coordinate their defenses. Itachi could use his fire - style jutsu to create a diversion while Kisame moves in for a surprise attack from another angle.
Itachi would be very strict in Naruto's training, but also very caring. Naruto would look up to Itachi and try to learn as much as he can from him. As Naruto grows, he might start to have his own ideas which could sometimes clash with Itachi's. But through communication and understanding, their relationship would become deeper. Itachi would share his past experiences with Naruto, which would make Naruto understand the complexity of the ninja world better, and in return, Naruto's innocent and determined nature would slowly change Itachi, making him more hopeful about the future of the ninja world.
Itachi's protectiveness can make Naruto more confident. Knowing that someone as powerful as Itachi has his back gives Naruto a sense of security. This allows him to take more risks in his training and battles, which in turn helps him grow stronger. For example, he might attempt more difficult jutsu without fearing too much about the consequences of failure because he believes Itachi will step in if things go really wrong.
In a fanfiction, Naruto and Itachi could be partners in a different dimension. Maybe they were brought there by some sort of strange jutsu. They have to find a way back home while also dealing with the unique problems of this dimension. Itachi's calm and strategic thinking combined with Naruto's determination and never - give - up attitude would make for an interesting dynamic.
Well, in fanfic, a female Itachi could bring a whole new dynamic to the Naruto universe. Her character might have some of the same traits as the male Itachi, like being highly intelligent and powerful. But as a female, she could also have different relationships with other characters. For Naruto, this could mean a different kind of mentorship or friendship. Maybe she could guide Naruto in understanding the Uchiha clan better, which could be really interesting.