Well, it could be that Naruto, for some reason, is abandoned in Iwa. Maybe he discovers some dark secrets about Iwa that make the villagers turn against him. He might then have to use his ninja skills and wits to survive and find a way out of the situation.
Maybe the main antagonist is the entire Iwa council. They might be the ones who order Naruto's abandonment because they fear his potential influence on Iwa. They would do everything in their power to keep him from uncovering their plans or causing unrest among the villagers.
One possible reason could be a threat from Iwa to Konoha. If Iwa was planning an unprovoked attack on Konoha, Naruto might take it upon himself to destroy Iwa to protect his village.
In this fanfiction, Naruto might run away to Iwa because he feels misunderstood in Konoha. Maybe he discovers some secrets related to his family that make him think Iwa has the answers. He could face many challenges on his way there, like avoiding capture by Konoha ninjas who think he's a traitor.
Well, one possibility could be that Naruto is banished from Konoha due to some false accusations. When he joins Iwa, he might start learning their unique jutsu and fighting styles. He could also face a lot of distrust at first from the Iwa ninjas because he's from Konoha. But as time passes, he proves himself and becomes an important part of Iwa, maybe even leading some missions against common enemies of both villages.
One possible plot development could be Naruto facing initial hostility in Iwa. Since he's from Konoha, the Iwa ninjas might be suspicious of him at first. But Naruto, with his determination and unique skills like the Rasengan, could gradually earn their respect. He might also learn new jutsu unique to Iwa and form new alliances, perhaps even finding a way to bridge the gap between Konoha and Iwa in the long run.
Naruto is obviously a very popular character in these fanfictions as he is the main character of the original series. In Iwa, characters like Deidara (who was originally from Iwa) often make appearances. His explosive jutsu and unique personality add a lot to the stories.
One great Naruto Iwa Admiral fanfiction is 'The Stone Admiral's Ascent'. It has an interesting plot where the Iwa Admiral character shows unique jutsu and strategic thinking. It really delves into the character's backstory and how they interact with the Naruto universe's existing elements.
Naruto could meet some young and upcoming Iwa ninja trainees. They might be curious about Naruto and his abilities from Konoha. These trainees could either look up to Naruto or be jealous of his fame, leading to various interactions. Also, there could be some old - timer Iwa ninjas who remember past events involving Konoha and have their own views on Naruto's presence in Iwa.
Another way is that he forms an unexpected alliance within Iwa. There could be a dissident group in Iwa who oppose the capture of Naruto. They might help him escape in exchange for some future favor or because they believe in Naruto's cause. Naruto has a way of inspiring people, even those who are initially his enemies, so this is a plausible scenario.
I'm not sure specifically as it depends on the author's creation. But it might involve Naruto having some sort of conflict with Kumo and then abandoning it. Maybe there are issues like political differences, or problems with the shinobi from Kumo that lead Naruto to this decision.