In such a fanfic, Naruto might have to face challenges in communication. Since he's stuck as a fox, he can't use normal human language easily. He may have to rely on body language or simple growls and howls to convey his feelings and needs to his friends. This could lead to a lot of misunderstandings at first.
He might have to figure out how to survive on his own. Maybe he'll start by looking for fresh water sources like springs or collect rainwater. He could also try to find food such as fishing in the island's waters or hunting small animals if there are any.
Sakura could be one. She's a skilled ninja and also Naruto's friend. She would likely use her medical ninjutsu knowledge to see if there are any physical or chakra - related reasons for Naruto's transformation and try to reverse it. Another one could be Kakashi. He has a lot of experience and knowledge. He might research in the old ninja scrolls to find a solution.
Well, he could get involved in a whole new set of adventures. Maybe he has to find a way to get back to his own world. He'd probably face some unique challenges like dealing with villains that only exist in that 'Road to Ninja' world. It would be a struggle for him to adapt and use his skills in a different environment.
Perhaps the baby fox has some special abilities. When it snuggles with Naruto, it could transfer some of its power to him, like a boost in his chakra or an enhanced sense of smell. This could then be used in his battles or in his search for new ninja techniques.
Another thing that could occur is that they encounter some strange creatures or phenomena inside the box. Naruto would be ready to fight, but Hinata might first try to understand the nature of these things. They'd have to combine their different approaches to deal with the situation, and in the process, their relationship would evolve, whether it's becoming better friends or something more romantic.
In the fanfic, being stuck in a blizzard, Naruto and Sasuke could share their life stories more deeply. Naruto might talk about his lonely childhood in a different way, and Sasuke could open up about his family's past. This extreme situation would force them to bond on a new level. Maybe they'd even discover new jutsu together while waiting for the blizzard to pass.
Well, he'd probably try to use his ninja skills in the Pokémon world. Maybe he'd use his speed to catch Pokémon faster than anyone. He could also use his shadow clone jutsu to battle multiple Pokémon at once.
They could use their ninja skills to try and break out of the box. Naruto might try his Rasengan, while Hinata could use her Gentle Fist to find weak points in the box's structure.
If Harry is stuck in Naruto's seal in fanfiction, he could potentially discover new forms of energy or power. Since he's used to magic, being in the seal might expose him to different types of energy like chakra in a very direct way. He could also make friends with the entities inside the seal, who could teach him things about Naruto's world that he would never have known otherwise. This could give him an edge when he finally gets out of the seal and has to interact with Naruto and the others.
They might try to change some past events. For example, Naruto could prevent some of the early tragedies in the village. Hinata might also get the chance to be more assertive earlier in her life, since she has Naruto by her side this time. They could also have an impact on the relationships between different ninja clans.