Naruto could potentially find some ancient ninja artifacts on the deserted island. These artifacts could hold great power or knowledge. He would then have to figure out how to use or protect them. There could also be some sort of mystery on the island, like a hidden cave with strange markings. Naruto, being the curious and adventurous type, would surely try to solve the mystery. This could lead to him learning new jutsu or uncovering secrets about the ninja world's past.
There's a chance it could be a spirit of some sort. In the Naruto world, there are many spiritual elements. A spirit that has been bound to the island for ages could appear to Naruto. This spirit could guide him to hidden treasures or teach him some ancient ninja wisdom that has been lost in the modern ninja world.
He could meet a lost shinobi from a different village. This shinobi might have been stranded there for a long time and has some valuable knowledge or skills that Naruto could learn from.
Another idea for the Naruto deserted island fanfic is that Naruto is sent to the island as a form of training. He initially struggles to adapt to the harsh environment. However, as time passes, he learns to control his chakra in new ways, perhaps by using the natural elements of the island. He could also meet a hermit on the island who teaches him some unique ninja techniques.
An adventure where they have to stop an evil force that is threatening both of their worlds. Naruto could bring his knowledge of sealing jutsu to prevent the evil from spreading, and Noire could use her leadership skills to gather allies.
They could have an adventure where Kakashi has to protect baby Naruto from some low - level bandits. Kakashi would use his Sharingan to quickly assess the situation and his lightning - style jutsu to fend them off while making sure baby Naruto is safe.
They could have adventures full of strategic battles. Shikamaru's intelligence would complement Naruto's impulsiveness. For example, in a mission against a powerful enemy ninja, Shikamaru could devise a complex plan while Naruto uses his determination and powerful jutsu to execute it. They might also face challenges within the team, like disagreements on how to approach a mission, but ultimately grow closer as comrades through these experiences.
They might get involved in a conflict between two rival clans. As brothers, they would have to figure out a way to bring peace. Naruto, with his charisma and ability to make friends, and Kiba, with his loyalty and combat skills, would work together to resolve the situation. For example, Naruto could talk to the leaders of the clans while Kiba provided security and used his senses to detect any signs of danger.
He could go on adventures to find rare medical herbs for Tsunade's research. Since he's her grandson, he might be more involved in her medical - ninjutsu related projects.
He could have adventures in Hera's realm. Maybe he has to face mythical creatures there to prove himself worthy of his new heritage. For example, he might encounter centaurs or minotaurs and have to use his ninja skills combined with any new powers from Hera to defeat them.
A possible plot for this fanfic could involve Naruto being teleported to a deserted island which has an abundance of lemon trees. As he tries to figure out how to get back home, he starts to experiment with the lemons. He might find that the lemons have some sort of energy that he can harness. This could attract the attention of some local island spirits or creatures. Naruto then has to use his ninja powers and the power of the lemons to either befriend or defeat these beings in order to find a way off the island.