It could be that Kumo has a rogue group within their village that wants to use Naruto for their own malicious purposes. They kidnap him in the chaos of a diplomatic visit or something similar. Once kidnapped, Naruto finds himself in a difficult situation as he is far from home. But he uses his never - give - up attitude and starts making friends with some sympathetic Kumo ninjas who help him in his fight against the rogues and eventually his escape back to Konoha.
One possible plot development could be that Naruto's friends in Konoha realize he's missing and start a search mission. They might suspect Kumo immediately due to the history of tensions between the two villages. Meanwhile, in Kumo, Naruto could be held in a secret location. Some in Kumo might want to use him as a bargaining chip against Konoha, while others might see his potential and try to turn him into an asset for Kumo.
Naruto could try to befriend some of the Kumo ninjas who might not be in favor of the kidnapping. By winning them over, they could help him escape. Also, he could use his knowledge of ninja techniques and his quick thinking. For example, he could use substitution jutsu to switch places with an object when the guards are not looking and then make a run for it.
If Naruto is kidnapped by Kumo in fanfiction, it could lead to a series of intense battles. Naruto himself might try to escape on his own using his ninja skills and the power of the Nine - Tails. His captors in Kumo would probably want to extract some sort of information from him, like the secrets of the Nine - Tails or Konoha's defense strategies. However, Naruto is a tough character and would surely put up a fight.
Maybe in the fanfiction, Naruto neglected Kumo because he was too focused on his own village's problems. But then something major happens in Kumo, like a powerful enemy targets them. Naruto realizes his mistake and goes to Kumo to make amends. He teams up with the Kumo shinobi, and they work together to fend off the threat. Along the way, he learns about Kumo's unique culture and forms strong bonds with their ninja.
Perhaps Naruto is in Kumo to search for a missing Konoha ninja. While there, he uncovers a conspiracy within Kumo that threatens both villages. He then has to team up with some of the Kumo ninjas who initially distrusted him to stop the threat.
If Naruto joins Kumo in fanfiction, it might start with Naruto being sent on a mission to Kumo as an ambassador of sorts. Once there, he becomes intrigued by their combat techniques and decides to stay for a while to train. He could get involved in Kumo's internal power struggles. For example, there might be a faction in Kumo that doesn't trust him and tries to drive him out, while another faction sees his potential and wants to keep him. His presence could also change the dynamics between Kumo and other ninja villages as they see Naruto's new allegiance.
One way could be a stealth mission. Shikamaru, with his high intelligence, could plan a strategy to infiltrate Kumo's hideout undetected. He could gather a small team of skilled ninja like Neji (if he were still alive in the fanfiction), Rock Lee, and Ino for mind - reading and communication. Then they could free Naruto and Hinata and escape before Kumo realizes what's happening.
One possible plot could be that Naruto goes to Kumo but is not well - received there. Maybe the people of Kumo are still suspicious of him because of his status as a Jinchuuriki. They could isolate him, and Naruto has to struggle to prove himself worthy of their trust. He might also face discrimination from some of the Kumo ninja.
Well, one possible plot could be that Fem Naruto goes to Kumo to seek new challenges and training opportunities. In Kumo, she might face discrimination at first because she's from Konoha. But as she shows her strength and unique skills, she gradually earns the respect of the Kumo ninjas. Maybe she forms an unlikely friendship with some of the Kumo shinobi and together they take on powerful enemies that threaten both Kumo and Konoha.
One possible plot could be that Naruto is on a mission near Wave and discovers a threat from Kumo ninjas. He decides to save Wave by using his unique skills and his knowledge of Kumo's fighting styles. Maybe he forms an alliance with some of the local Wave defenders and together they outwit the Kumo forces.