Sakura is the central character. In addition, there could be a mysterious old woman who seems to know more about Sakura's power than she does herself. This old woman could be a guide of sorts, giving Sakura hints about how to control and understand her visions better. There might also be a rival character, perhaps a jealous classmate named Akiko, who tries to undermine Sakura because she's jealous of the attention Sakura gets due to her unique ability.
Obviously, Sakura would be one of the main characters since the title centers around her. There might also be her friends or family members who could be either supportive or skeptical of her ability to see the dead.
Obviously, Harry himself is a central character. Hermione and Ron are also very likely to be in it as his closest friends. Dumbledore may also play an important role, as he often guides Harry in the original stories. He could be the one Harry confides in about his new ability to see the future.
Well, perhaps there could be a plot where Sakura sees the future of her own love life. She might see herself with someone unexpected, and then she has to navigate her current relationships and feelings while also trying to understand how this future might come to be. It could also be that she sees a future where her special ability is revealed to the whole world, and she has to deal with the consequences, like being hunted by those who want to use her power for their own gain.
A powerful vampire who also has some sort of mind - control ability could be the main antagonist. He might be trying to use Bella's future - seeing ability for his own evil purposes, like taking over the vampire world or destroying the werewolves.
It could be a new dark wizard that they see in the future. Maybe someone who was overlooked during the fight against Voldemort but has been secretly gathering power.
It could be a time - traveling villain who doesn't want Sakura to succeed in her journey in the future. This villain might be from Sakura's own time but has different motives in the future setting.
There could be her family members. Her parents might play a role in either supporting or not believing her new - found ability. And her siblings could be either jealous or in awe of her. Also, there could be a wise old man or woman in the village who has some knowledge about seeing the future and can guide her.
The Akatsuki members would be the main ones. It could include Itachi, who is known for his complex character and powerful abilities. His relationship with Sakura could be an interesting aspect, whether it's one of mutual respect or a more adversarial one.
Well, obviously Sakura Apprentice herself is a main character. Often, there might be her mentor or the person she is apprenticed to as another important character.
It really depends on the specific fanfiction. It could be a young samurai who is on a quest related to the sakura scroll. Maybe he is the one tasked with protecting it or uncovering its secrets.