The most important character is Stargirl. She's an enigma, full of surprises with her eccentricities. Leo Borlock matters a great deal as he has a complex relationship with Stargirl. He is both attracted to her uniqueness and at times embarrassed by it. Hillari Kimble plays an important role as she represents the conservative and judgmental part of the school community. There are also characters like Archie, who gives advice and has a certain wisdom, which influences the story.
In the 'Stargirl novel', Stargirl is the central figure. She's the one who brings all the change and stirs up emotions in the school. Leo Borlock is crucial as he gets involved with Stargirl and his perspective shows the reader how different Stargirl is. Dori Dilson is also important as she is one of Stargirl's few friends at the start. And Mr. McShane, the principal, is important in the way he manages the situation regarding Stargirl in the school.
Perry is an important character. He is someone Stargirl has a connection with. Their relationship adds depth to the story. Also, there are her classmates and the people in her community who react to her in different ways, like Hillari Kimble who is kind of an antagonist as she doesn't like Stargirl at first.
There is Stargirl, a girl full of life and originality. She dresses differently, acts differently and has a big heart. Leo is another main character. He is initially a bit of an observer at school, but when Stargirl arrives, his world is turned upside down. And then there are the classmates, like Hillari Kimble who is sort of the antagonist in a way as she is one of the main ones who has a problem with Stargirl's uniqueness and tries to make her life difficult at school.
Well, clearly Stargirl is one of the main characters. And probably the person she falls in love with would be another main character. But without more context, it's hard to say exactly who that might be.
Courtney Whitmore (Stargirl) herself is, of course, essential. But adding characters like Pat Dugan, her step - father, can bring in more family - dynamic elements. He could be a source of wisdom and support for Stargirl in the story.
There may be a love interest or a supporting character like an old-timer who has been on the waterfront for years. The love interest could provide motivation for the protagonist to make changes, and the old - timer could offer wisdom and historical context about the place and how it has changed over time.
Lyddie is obviously the most important character. She is the protagonist and the story revolves around her journey. Then there's her mother, who is an important figure in Lyddie's past and whose actions have an impact on Lyddie's life. Rachel, Lyddie's sister, is also important as Lyddie has a strong sense of responsibility towards her.
The protagonist is definitely an important character. His actions and thoughts drive the story forward. There might also be some secondary characters who interact with him and help to show how much of an outsider he really is.
Eragon is the most important character. He is the protagonist, a young Dragon Rider. Saphira, his dragon, is also crucial. She is his partner and has her own unique personality. Brom is an important character too. He is a storyteller who becomes Eragon's mentor and helps him on his journey.
In Flatland novel, the Square is a central character. He is the narrator for most of the story and his journey of discovery forms the main plot. There is also his grandson, who shows the next generation's potential for different thinking. And the Priest - Circles are important as they are the ones who enforce the social and religious rules in Flatland.
In 'Heidi the novel', Heidi is the key character. She is a young girl with a pure heart and a love for nature. Her grandfather, who initially seems a bit of a recluse but has a warm heart deep down. Peter, he's the boy who takes care of the goats and is Heidi's playmate. He has his own simple charm. Clara is another significant character. She is a frail, wealthy girl from the city. When Heidi goes to the city to be her companion, their lives become intertwined. The interactions between these characters drive the story forward and show different aspects of human nature and life in different settings.