Sakura, of course. There could also be a wise old wizard who helps her understand the new world she's in.
In this fanfiction, Sakura is the main character. Besides her, there could be a group of rebels fighting against an unjust regime in the other world. Maybe a young mage who is initially jealous of Sakura's arrival but later becomes her friend. And a shape - shifting creature that can take on different forms and provides Sakura with valuable information about the secrets of the other world.
Sakura could have interactions with the Weasley family. Ginny Weasley might become her friend and they could have girl - talk about magic and boys. Fred and George could also be part of her story. They might play some pranks on her at first but then become good friends. And don't forget Neville Longbottom. Sakura could help Neville gain more confidence in his magic abilities as they study together in the Hogwarts library.
In this 'harry potter goes to the sixth world fanfiction', we would expect Harry Potter. Besides him, there might be new wizards or witches native to the sixth world. They could have their own unique powers and personalities. Maybe there are also some half - magical beings that Harry has never encountered before. These new characters would add more complexity and freshness to the story.
There could be a wise old wizard who becomes Kaneki's mentor in the new world, guiding him on how to use the magic there.
Well, it could be about Sakura exploring a magical new world filled with strange creatures. Maybe she has to find a way back home while making new friends along the way.
Obviously, Harry would be one of the main characters. There could also be local Harlem residents like a street - smart kid who shows Harry around. A jazz singer could be another character, perhaps someone with a mysterious past that Harry gets involved with.
A military general could be a main character. He might be the one leading the charge in exploring this new world and dealing with any threats that come their way.
Well, in addition to Sakura, there might be a strict but fair psychiatrist. He could be a key character as he tries to diagnose and treat Sakura. There could also be a group of patients that Sakura befriends. For instance, a young girl who is in the hospital due to severe anxiety and an older man who has hallucinations. These characters could interact with Sakura in different ways, some being helpful, others being a hindrance to her progress in the mental hospital.
A young girl who has always been fascinated by Sakura could be a main character. She might be on a journey to see the most amazing Sakura blossoms.
Kakashi could also be a great addition. As a mentor figure, he could guide Sakura in understanding and controlling her newfound powers from her rebirth. And then there are the villains. Orochimaru could be interested in Sakura's rebirth if he senses some new and powerful chakra within her. He might try to capture her for his own experiments.
Well, Sakura is definitely one of the main characters, since it's about her going to the past.