The princess is central. There may be her family members, like her father the king or her mother the queen, who play important roles in the story. And then there are characters like the young stable boy who becomes an unexpected ally to the princess in her adventures. Sometimes, there could be a fairy godmother - like character that guides her.
There could be a scientist character who is trying to study Alexandria's genesis. This character might be fascinated by the genetic anomaly and wants to understand it better. They could play a crucial role in either helping or hindering the characters with the genesis, depending on their motives. Maybe they see it as a way to gain fame and fortune, or perhaps they truly want to help the 'affected' individuals.
I don't know the exact main characters without more information about the 'alexandria novel'. They could be locals from Alexandria, like fishermen or merchants.
One popular Princess Alexandria fanfic could be 'The Adventures of Princess Alexandria in the Enchanted Forest'. It's a great read as it takes the princess on a journey filled with magical creatures and challenges. Another might be 'Princess Alexandria and the Lost Kingdom' which delves into her quest to restore a forgotten realm. And 'Princess Alexandria's Secret Talent' shows a different side of the princess.
The main character is the sakura secret princess. Alongside her, there could be a young and adventurous boy from a neighboring village who stumbles upon her secret. There might be a powerful queen mother in the story who has her own motives regarding the princess's secret. And then there could be a mysterious figure in the shadows, an agent of an unknown force, who is constantly watching the princess and trying to figure out her secret, adding an element of mystery and suspense to the fanfic.
Obviously, one of the main characters would be the demon. Another would be the princess. And depending on how the story is written, Naruto and some of his friends like Sasuke or Sakura might also be important characters as they could be involved in the events related to the demon and the princess.
Princess Bluebelle is likely one of the main characters. And probably some of the well - known My Little Pony characters like Twilight Sparkle, Pinkie Pie etc. might also be involved depending on the plot.
Obviously, Allie is one of the main characters as she is in the title. She is likely to be a princess with a connection to Pokemon.
Obviously, the sakura princess herself is a main character. She is often depicted as kind - hearted, beautiful and with a strong will.
Obviously, Hermione would be the main character as the title implies. But it's likely that Harry and Ron will also be important characters. They are her closest friends in the original series, so they will probably play significant roles in this fanfic too, perhaps helping Hermione in her princess - related adventures or dealing with the consequences of her new status.
Well, of course, Princess Peach and Rosalina are the main characters. Princess Peach with her pink dress and kind heart, and Rosalina with her flowing blue gown and celestial powers. But there could also be other supporting characters. For example, Mario might be a part of the story in some way. Maybe he's a bit jealous of Peach's new friendship with Rosalina at first. And the Lumas that follow Rosalina could also play a role, like they might be the messengers between the two main characters' worlds.