His character could become more jaded. In the ANBU, Naruto would have seen a lot of the darker side of the ninja world. He might be less naive and more calculating. For example, he would be more hesitant to trust people immediately like he used to.
Well, in a fanfiction where Naruto joins ANBU, his training would intensify. He'd be trained by some of the toughest ANBU veterans. His skills in combat would become more refined as he'd learn to use weapons like kunai and shuriken with more precision. He may also develop new jutsu that are more suitable for covert operations. His growth as a ninja would be different from the regular path, focusing more on secrecy and assassination if required.
In fanfiction, an older Naruto may have a more refined sense of leadership. He has seen more, experienced more battles and political situations. So, he might be more diplomatic in his approach compared to his younger self.
For Naruto in Anbu, you could start with his initial brashness still showing but slowly being tempered by the strict Anbu code. As he interacts with Yugao, he starts to see things from a different perspective. Yugao, on the other hand, could start as a reserved and focused ninja. When she meets Naruto, his energy starts to break down her walls. You can show their development through their conversations and how they react to different situations together.
The character could start off being underestimated by others in the Anbu because of their blindness. But as they face various challenges and succeed, they gain respect. For instance, in a mission where they have to infiltrate an enemy base, they use their blindness to their advantage by being less detectable in the dark.
When writing their character development, consider the challenges they face. Naruto in the Anbu has a dark side to his work that Ino may not understand at first. Have Ino be curious and try to understand Naruto's world, which in turn makes Naruto more willing to open up. For Ino, have her face some self - doubt in her ninja abilities, and Naruto's belief in her can boost her confidence. Their relationship should be a two - way street where they both evolve based on their interactions and the situations they encounter together.
Naruto may learn to suppress his emotions better in ANBU fanfictions. This would be a big step for him as he is known for wearing his heart on his sleeve. Iruka, on the other hand, could become more strategic. He might start to think more like a true ANBU operative, planning several steps ahead. This would change his character from just a teacher to a more complex and capable ninja. Also, their bond could strengthen in the face of the more dangerous and secretive ANBU world as they rely on each other more.
In this kind of fanfiction, one possible plot development could be Naruto having to deal with the secrecy aspect of ANBU. He might struggle with the morally grey missions they undertake. For example, he could be sent to spy on an old acquaintance. Naruto, being Naruto, might try to find a more positive solution to the situation rather than blindly following orders.
Typically, Naruto's bold and energetic personality contrasts with Hinata's shy yet determined nature. In an ANBU setting, Naruto might be the one to rush into action first, while Hinata uses her Byakugan to assess the situation more carefully. Their relationship could start as comrades in the ANBU, with Naruto gradually realizing Hinata's strength and Hinata becoming more confident around Naruto.
In ANBU fanfictions about Naruto and Iruka, their relationship often takes on new and exciting dimensions. Naruto, with his usual exuberance and determination, might be guided in the more secretive and dangerous ANBU world by Iruka. Iruka, being a caring figure in Naruto's life, could be a source of stability for Naruto as he faces the harsher aspects of ANBU missions.
In some fanfictions, Naruto's life in Anbu could lead to a significant change in his character. He may become more withdrawn and brooding as he deals with the darker side of the ninja world that Anbu often encounters. His relationships with his friends might also be strained as he has to keep parts of his Anbu life a secret. This could create a lot of drama and tension in the story.