There could also be a friend or a family member who plays a role in either causing or helping to heal the 'burning heart'. For example, a wise older relative who gives advice during the difficult times.
There might be a love interest. If the theme is related to love and heartbreak, there would be a character with whom the main character has a romantic relationship that causes the 'burning heart' situation.
It might be about self - discovery. Maybe the protagonist experiences situations that are so intense they 'burn' in their heart, leading them to discover new aspects of themselves.
I'm not sure specifically as I haven't read it in detail, but they could be environmental activists. Given the title, it would make sense for those who are trying to stop the 'world from burning' to be central characters.
I'm not sure as I haven't read the specific 'unbreak my heart novel'. But usually in this kind of novel, there would be a protagonist who is likely to be the one with the broken heart.
I don't know the specific main characters in this novel as I haven't read it. Maybe there's a young protagonist, male or female, who is on a journey of some sort.
Perhaps it's a story about a single character and their journey, with the people they meet along the way being important secondary characters. The main character could be someone who has had a life - changing experience that will be 'forever in my heart', and the other characters help shape that experience.
Since I don't have the 'hear my heart novel' at hand, it's difficult to say exactly who the main characters are. However, in most novels, the main characters are those who drive the plot forward. They could be characters with a strong goal or desire. For example, in a coming - of - age story, it might be a teenager trying to find their place in the world. In a mystery novel, it could be the detective or the person who has a connection to the mystery. In the 'hear my heart novel', it could be a character who has a heart - related theme, perhaps someone who has a special ability to understand others' emotions deeply or someone who is on a journey to heal their own broken heart.
Since I haven't read the novel, I can't say for sure. But it could be a couple, like a man and a woman where one of them is the 'heart - player'.
Maybe there is a strong - willed female lead. She could be the one who has to steel her heart in a male - dominated world. For example, she might be facing discrimination or hardships in her career or personal life, and she has to toughen up. There could also be a mentor - like character who helps her along the way.
I don't know for sure without reading the book. But it's likely that the sisters are the main characters. There could also be other family members or friends who play important roles in the story.
I'm not sure specifically as I haven't read this novel. But usually, there would be a protagonist, perhaps a young woman or man who is at the center of the story's emotional journey. There might also be a love interest, like a charming person who catches the protagonist's heart.