Obviously, Naruto is one of the main characters. His friends like Sasuke, Sakura, Kakashi, and others are also likely to be main characters as they are the ones protecting Naruto.
Perhaps there is a scenario where Naruto is framed for a crime he didn't commit. His friends, believing in his innocence wholeheartedly, protect him from the angry villagers and work hard to clear his name. They might use their unique skills, like Sasuke's sharingan to find clues, and Sakura's medical knowledge to keep Naruto in good health during this tough time.
Often, it could be the Akatsuki. They are always after the power of the tailed beasts, and with Naruto being protected by the Kyuubi, they would be major antagonists. They might come up with new and devious plans to try and get to the Kyuubi within Naruto.
In the 'naruto is protected by sasuke fanfiction', Sasuke's protection of Naruto could be multi - faceted. Sasuke, being a powerful ninja, would first of all use his physical strength and speed to block attacks aimed at Naruto. Emotionally, his bond with Naruto would make him extremely vigilant. He might sense Naruto's distress from afar and rush to his aid. In terms of strategy, Sasuke would likely plan their movements carefully when they are in dangerous situations, ensuring Naruto is always in a relatively safe position. His ability to quickly analyze a battle situation and react accordingly would be crucial in protecting Naruto.
A group of monkeys might be the main protectors. Monkeys are known for their agility and intelligence. They could swing from tree to tree, launching surprise attacks on Naruto's foes. They could also use their knowledge of the forest terrain to lead Naruto to safety.
In some fanfictions, the Kyuubi's protection might lead to Naruto having a special bond with nature. Since the Kyuubi is a powerful force, it could influence Naruto's chakra in a way that makes him more attuned to the natural elements around him. This could give him an edge in battles, like being able to manipulate the environment in ways others can't.
Well, perhaps when Sasuke and Naruto are cornered by a much stronger foe, and Sasuke uses his Sharingan in a unique and unexpected way to protect Naruto. It could also be exciting when Sasuke has to make a split - second decision to sacrifice something important to save Naruto in the fanfiction.
The fanfiction could start with Naruto being poisoned. He's weak and unable to defend himself. But then, small animals like squirrels and rabbits start bringing him herbs that have healing properties. Larger animals like deer stand guard over him while he recovers. As he gets better, he forms a bond with these animals. They then continue to protect him as he goes on his journey, and Naruto, in turn, uses his ninja skills to protect the animals' habitats from other threats in the ninja world.
In a fanfiction where Naruto and Madara are friends, it could completely change the Naruto storyline. Their friendship might start from a mutual understanding of their strong wills. Naruto, with his belief in redemption, could see past Madara's actions. And Madara, who has been alone for so long, might be drawn to Naruto's positive energy.
One way for Naruto and Ibiki to be friends in a fanfiction could be through a shared love for the village. Ibiki, who has dedicated his life to protecting Konoha, sees Naruto's potential to be a great protector. Naruto, in turn, admires Ibiki's loyalty. They often meet in secret to exchange stories about their ninja lives, and over time, this connection deepens into a strong friendship.