One possible plot could be that Naruto is discovered to have an extraordinary natural talent that is recognized by a powerful figure, like the Third Hokage. This figure decides to fast - track Naruto's training and place him in the ANBU. In the ANBU, Naruto could face discrimination from the other members due to his age and being the Jinchuriki. But he overcomes this with his determination and starts to show his unique abilities, like his unrivaled stamina. He might be sent on missions where his innocent perspective actually helps in solving problems in unexpected ways.
Well, the plot could start with Naruto being secretly trained by an unknown master from a very young age. This master sees Naruto's potential and trains him to be an ANBU - level ninja by age 5. In the fanfic, Naruto could be given special missions that are related to the Akatsuki's early activities. He might use his shadow clones in innovative ways to gather intelligence. Since he's so young, the other ninja might underestimate him, but he proves them wrong time and time again. He could also form an unlikely friendship with an older ANBU member who becomes his mentor.
The plot could involve an Anbu member protecting the girl who is a Naruto fan. Maybe she has some special knowledge about Naruto that is important in the Naruto world they live in, and the Anbu is tasked with keeping her safe from those who might want to use her knowledge for bad purposes.
Perhaps Naruto in the Anbu has a personal mission that goes against the village's orders. For example, he might befriend someone from an enemy village who is actually innocent but is being targeted by Konoha. When the village refuses to listen to his pleas, he decides to leave. He'll use his Anbu abilities to protect his new friend and find a new place where they can both be safe, away from the political drama of the ninja villages.
Maybe in the fanfic, Team 7 in ANBU is tasked with protecting a powerful and important shinobi from another village who has come to Konoha for peace negotiations. Naruto tries to befriend the visiting shinobi, Sasuke is constantly on guard against any possible threats, and Sakura is ready to heal any injuries in case of an attack. There could be internal conflicts within Team 7 as they deal with different approaches to protection.
One possibility is that Naruto is sent on a top - secret mission by ANBU. Maybe he has to infiltrate a powerful enemy organization. His disappearance could be part of a long - term undercover operation where he has to cut off all ties with his friends and the village for a while to avoid suspicion.
One possible plot could be that Naruto is tasked with infiltrating a rogue ninja group that has ties to a powerful enemy of Konoha. As an undercover ANBU, he has to pretend to be a rogue ninja himself to gain their trust. Along the way, he discovers secrets about his own family and the true nature of the threat against Konoha.
One possible plot could be that Kurenai has some sort of influence on Naruto's decision. Maybe she sees his potential in a different way than others. She could encourage him to join ANBU to better protect the village and its people. Naruto, being influenced by her words and perhaps having a sense of admiration for her, decides to take on the challenge of joining ANBU.
Well, one major plot change could be in the power dynamics. Since Naruto in Anbu is likely more skilled and experienced. He might take a more dominant role in Team 7's missions. For example, he could quickly assess and handle dangerous situations that the original Team 7 might struggle with. This could also change the relationships within the team. Sasuke might be more competitive towards Naruto, seeing him as an even greater rival. And Sakura might have more admiration or fear towards Naruto because of his Anbu status.
One possibility is that Naruto gets caught in a powerful genjutsu that makes everyone forget him. He might then struggle to find a way to break the genjutsu on his own. He could start to question his own identity and purpose, as being an Anbu, his very existence in the shadows becomes even more lonely without anyone's recognition.
One possible plot twist could be that Naruto, being at Itachi's age, has already mastered some of the more advanced jutsu much earlier. For example, he might have learned the Sharingan - like abilities through some unique encounter, which would completely change the power dynamics in the Hidden Leaf. This would also lead to a different relationship with Sasuke, as Naruto would be more of an equal in terms of power and mystery.
No. Naruto at age 5 was too young. ANBU members are typically older, more experienced ninja. They need to have a deep understanding of the ninja world, its politics, and be able to handle complex situations. A 5 - year - old Naruto was more focused on making friends and getting recognition from the villagers. His main concern was not being alone and getting through the academy training. He was nowhere near ready to take on the responsibilities of an ANBU.