Obviously, Anakin is a crucial character. The slaves themselves would also be important. There could be a young slave boy or girl who Anakin befriends and who serves as a symbol of hope for the others. And the slave masters, as the antagonists, are important too.
The plot might center around Anakin's moral struggle. On one hand, he has the Jedi teachings, but on the other, his own past as a slave. This internal conflict could add depth to the story as he decides how far he's willing to go to free the slaves. He may also have to deal with the consequences of his actions in the eyes of the Jedi Council.
Obviously Naruto and Kaguya are the most important. Naruto as the one to free Kaguya, and Kaguya as the one being freed.
Another way in fanfic could be that Anakin discovers a plot by the slavers that is against the greater good or some galactic law. By exposing this, he forces the system to free the slaves. He may also inspire the slaves themselves to rise up and demand their freedom, using his presence and the idea of Jedi - associated freedom as a catalyst.
The main characters are Naruto and Kurama, of course. Naruto is the protagonist who wants to free Kurama. Kurama is the nine - tailed fox that is sealed within Naruto and is the one being freed.
The legal system in some fanfic settings might not recognize slavery as an illegal practice immediately. Anakin would have to fight through bureaucracy and convince lawmakers to change the laws. There could also be cultural acceptance of slavery in certain areas, and Anakin would have to overcome the deeply - rooted beliefs of the people there.
Anakin's mother, Shmi, would likely be a very important character. Since Anakin is not being trained as a Jedi, he would be more focused on his family. Shmi's influence on Anakin would be even greater, and she could play a role in guiding his actions and decisions, especially in relation to the local community on Tatooine.
Obviously, Anakin would be the main character. His mother, Shmi, would also play a significant role. There could be his friends from the pod - racing days like Kitster. And perhaps some Tusken Raiders who might have a different relationship with Anakin since he stays on Tatooine. Maybe they would see him as a more permanent threat or, in an interesting turn, a potential ally in some local matters.
The main characters would be Anakin Skywalker and Darth Plagueis. Anakin, a powerful Force - sensitive, is the focus of the training. Darth Plagueis, a Sith Lord, brings his knowledge of the dark side of the Force to the table. There may also be other supporting characters like the Jedi who might notice Anakin's change in behavior or Padmé, Anakin's love interest, who could be affected by his new training and the path he is on.
Obviously, the members of the Jedi council would be main characters. Yoda, for instance, would play a crucial role. His wisdom and experience would lead him to question Anakin's motives and the truthfulness of what he says.
His mother, Shmi, would definitely be a main character. She could play an even more important role in Anakin's life, guiding him in using his abilities for the good of Tatooine. Also, Watto, the junk dealer, could be a significant character. Their relationship might evolve from one of slave - owner and slave to something more complex, like a grudging friendship or a business partnership as Anakin grows older and more skilled.