In this fanfic, Naruto might face tougher and more secretive missions. He could be trained in new and deadly ninja techniques specific to ANBU. Also, his relationships with other characters might change. For example, he might become more distant from his old friends as ANBU work often requires secrecy.
She might convince him by showing him the long - term benefits for the village. For example, she could tell Naruto that in ANBU, he can prevent threats before they become major problems.
One challenge would be the secrecy. Naruto is used to being open and honest with his friends, but in ANBU, he has to keep things hidden. Another is the new type of missions. He may not be used to the stealth and assassination - type missions that ANBU often undertakes.
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.
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, 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.
Naruto's personality might become more reserved initially. The Anbu experience often makes ninjas keep their emotions in check. So, he might not be as boisterous as the original Naruto. For Sasuke, he could be more on edge around Naruto. He would sense the change in Naruto and feel pressured to keep up. Sakura might become more cautious too. She would see the more serious side of Naruto and might try to be more like him in terms of being focused during missions.
He would likely become more secretive. Since ANBU operates in the shadows, Naruto would have to keep a lot of things to himself, which is a big change from his usually open - minded self. Also, the death of Asuma could make him more ruthless in combat, as he realizes the harsh reality of the ninja world. He may still hold onto his core values of protecting his friends and the village, but his methods could be more extreme in the ANBU.
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.