One possible plot could be Naruto facing the internal politics of ANBU. He might struggle to adapt to their more secretive and sometimes morally gray operations compared to his usual straightforward ninja way. For example, he could be assigned to a mission where he has to spy on a former ally, creating an internal conflict within him.
Maybe Naruto joins ANBU to keep an eye on potential threats to the village that emerged after the war. He could use his new position to try and build bridges between different ninja clans and villages that are still suspicious of each other. He might start by recruiting some of his friends from other villages for joint training exercises within the ANBU framework.
If Naruto joins ANBU after the war in fanfiction, it could lead to some interesting character developments. He would have to deal with the darker side of the ninja world that ANBU often encounters. This might make him more cynical or, on the contrary, he could try to change ANBU from within. He'd be able to use his Uzumaki powers and his Sage Mode in more covert operations, which would give Konoha a huge advantage. Also, his relationship with other ANBU members would be complex. Some might respect him immediately because of his war hero status, while others might be skeptical of his more open - minded and friendly ways.
In such a fanfiction, the plot could involve Naruto being constantly overlooked by the village. Fed up with this, he decides to join ANBU to prove his worth. He might face challenges like distrust from his ANBU comrades at first because of his reputation. But as he goes on missions, he shows his skills and determination, gradually earning their respect and changing their perception of him.
Well, in such a fanfiction, perhaps Naruto has just lost Sasuke again and is deeply depressed. The ANBU, seeing his skills and his need for a distraction, recruit him. He starts off being a bit of a misfit in ANBU, not following all the rules because of his independent nature. But as he continues, he starts to understand the importance of their work. He might even form new bonds with his ANBU comrades, which slowly help him come out of his depression.
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 this fanfiction scenario, Naruto joining ANBU after the Chunin Exams could lead to a major shift in his relationships. His friends like Sasuke and Sakura might not understand his decision at first. Naruto could gain access to new and powerful jutsu within ANBU. Also, he might face internal conflict as the ANBU's sometimes morally gray missions could clash with his own values of protecting everyone and being a hero in the traditional sense.
Well, one possible plot development could be Naruto joining the ANBU to seek revenge for Asuma's death. He might use the ANBU's resources and training to become stronger and hunt down those responsible.
One plot twist could be that the person who cheated on Naruto actually has a very good reason, like they were forced to do it to protect Naruto from a greater threat. Another could be that in ANBU, Naruto discovers that the cheating incident was part of a larger conspiracy against him. Maybe his new ANBU teammates turn out to be related to the cheater in some way, creating a lot of internal conflict for Naruto.
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.
In this kind of fanfiction, Naruto might face some really tough and secretive missions in ANBU. He could be trained in new and deadly ninja techniques. Maybe he would also form some unexpected alliances with other ANBU members, learning from their different skills and experiences.
Well, Naruto might face a whole new set of challenges. In the ANBU, he could be pushed to his limits physically and mentally. Maybe he'd use his unique skills in stealthier ways compared to his normal fighting style. Also, his relationships with other ANBU members would be interesting to explore, as he's a bit of an outlier with his loud and brash personality.