One great fanfiction could be 'The Unlikely Bond'. In this story, Naruto discovers a side of Itachi that no one else knew. It shows how their friendship could have developed despite the initial differences. Naruto's optimistic nature starts to break through Itachi's cold exterior.
Another challenge is the secrecy that Itachi has to maintain in the original story. If he becomes friends with Naruto, how does he keep his true identity and motives hidden from the other characters in Konoha? Itachi is a master of deception, but Naruto is not very good at keeping secrets. This could lead to some tense situations where their friendship is almost exposed and puts them both in danger.
One possible plot could be that Naruto, with his unwavering belief in the good in people, manages to break through Itachi's stoic exterior. They start training together secretly. Naruto learns some of Itachi's unique jutsu and in return, he teaches Itachi about his never - give - up attitude. This newfound friendship also makes Naruto question the Leaf Village's view of Itachi, leading to a re - evaluation of the whole Uchiha massacre situation within the village.
One good plot could be that Itachi, before his actions against the Uchiha clan, secretly trains Naruto. He sees the potential in Naruto to bring peace to the ninja world and wants to help him grow stronger. This could lead to some interesting interactions where Itachi has to hide his intentions from his own clan and from the Akatsuki.
The plot should also incorporate elements from the original Naruto universe well. It could be about them teaming up against a new threat that neither could face alone. Maybe they have to use Itachi's sharingan abilities and Naruto's chakra control together. This makes the story feel like it belongs in the Naruto world. Also, the fanfiction should explore their different outlooks on life. Naruto is more optimistic while Itachi has seen the dark side of the ninja world, and seeing how they influence each other is really interesting.
A good fanfiction in this regard would have a strong understanding of both characters. For example, Itachi's complex past and motives need to be accurately portrayed. Naruto's growth and development should also be in line with his character in the original series. If a fanfiction can show how these two very different characters complement each other, it's on the right track.
One possibility for a Naruto and Itachi best friends fanfic could be that Itachi, instead of massacring his clan, finds a way to resolve the conflict with the help of Naruto. Naruto, with his unwavering belief in friendship, could convince the Uchiha clan and the village elders to come to a peaceful agreement. Itachi, seeing Naruto's positive influence, becomes his close friend. They could then train together, with Itachi teaching Naruto some of the more advanced Uchiha jutsu, and Naruto in turn sharing his own unique ninja way with Itachi.
Their friendship could also lead to a different perspective on the Uchiha clan's situation. Itachi's actions were complex and his friendship with Naruto could have made Naruto more involved in the Uchiha clan's affairs. This might have led to a different solution to the conflict between the Uchiha clan and Konoha, preventing the massacre. In turn, this would have a huge impact on the political situation in the ninja world.
Another element is the way they interact with the rest of the Naruto universe. For example, how their friendship affects Naruto's relationships with Sasuke, or how Itachi's actions within the Akatsuki are influenced by his newfound bond with Naruto. It's also common to see them working together to solve problems in the ninja world, which showcases their combined strengths.
One popular 'naruto and itachi friends fanfiction' is 'The Unlikely Bond'. In this story, it shows how Naruto, despite the complex situation between Konoha and Itachi, gradually forms a deep friendship with Itachi. It's really interesting to see how they interact and support each other through various challenges.