Well, it could be a very creative take on the Naruto story. The author might be exploring themes of second chances, the power of the divine, and the importance of Naruto to the Naruto - verse. Since Naruto is such a central character, his revival by Kami could change the entire course of the story. It might lead to him uniting different ninja clans in a way he couldn't before, or it could be about him facing new and even more dangerous threats that only he, with his new - found life, can handle.
Obviously Naruto is one of the main characters as he is the one being revived. And Kami, who is performing the revival, is also a crucial character. There might also be other characters like Sasuke, Sakura, and Kakashi who could be involved in the story after Naruto's revival. For example, Sasuke might be initially skeptical about Naruto's return or Sakura could be overjoyed and help Naruto get back to his normal self.
Maybe it's a completely new and unknown kami. A kami created specifically for this fanfiction. This kami could have unique powers and a different view of the ninja world compared to the existing characters in Naruto. It would add a fresh and exciting element to the story.
Maybe it's an existing character from Naruto who has been elevated to Kami status. For example, Tsunade could be turned into a Kami, and Naruto's relationship with her could be a very different dynamic from their previous ninja - leader relationship. Or it could be Kaguya, who was already a very powerful being, and in this fanfiction, she reforms and becomes a Kami and Naruto's wife.
One consequence could be that Naruto is seen as a hero by some, but also as a rule - breaker by others. The ninja world has rules about bringing back the dead, and Naruto's actions might stir up controversy. Some might fear that this new ability of his could be misused. Haku, on the other hand, would have to adjust to a world that has changed since his death. He might face challenges in reconnecting with his old friends or finding his place in the new ninja world.
In fanfiction, the 'kami' could be an original deity created by the author. This new 'kami' could have its own motives and reasons for giving a gift to Naruto. Maybe it's a kami that has been observing Naruto's journey and decides to interfere to help him achieve a greater purpose. It could be a kami associated with nature, like a kami of the wind or the fire, and the gift could be related to that element.
Maybe Jiraiya. Since Jiraiya was Naruto's mentor and taught him a lot of things. He might have some knowledge about summoning kami and pass it on to Naruto.
In the Naruto universe, bringing someone back from the dead is extremely difficult. While there are some jutsu like the Edo Tensei that can reanimate the dead, it has its limitations and is often considered dark magic. For Naruto to revive Jiraiya, he would need to find a way around the natural laws of life and death. However, in fanfiction, anything is possible as it allows for creative interpretations and bending of the established rules.
Perhaps it could be a female version of an existing kami from Naruto lore. For instance, a female counterpart of the Sage of Six Paths. She would have vast knowledge and power, and her training of Naruto would be a way to pass on that ancient wisdom and strength.
Many 'kami naruto fanfiction' pieces tend to blend the spiritual elements of Kami with Naruto's more physical and combat - oriented world. They might explore how Kami's existence affects the balance of power in the ninja villages. Also, these fanfictions sometimes create new relationships between Kami and other characters in the Naruto universe, like Kami having a special bond with Kakashi or Sasuke in some stories.