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.
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.
If Naruto joins ANBU after the war in fanfiction, his personality would experience a significant shift. His once boisterous and outgoing nature might be replaced by a more stoic and calculating one. He would need to be more discreet in his actions and words. The trust - building that he was so used to in his normal ninja life would be different in ANBU. He would have to be more guarded about who he trusts, which could make him seem a bit colder on the outside. But deep down, his kind heart would still be there. He'd just be more careful about showing it, as ANBU's world is full of deception and he can't afford to be too naive.
His relationship with Sasuke would be interesting. Sasuke might be initially suspicious of Naruto's decision to join such a secretive group. But Naruto could convince Sasuke that he's doing it for the greater good of the village and the ninja world, and they could end up working together on some behind - the - scenes missions.
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.
In some fanfictions, Naruto might join Anbu because of Sakura to prove himself worthy of her. Maybe he thinks that by becoming an elite Anbu member, he can show her that he's strong and reliable.
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, 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.
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.
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.