Well, there is the lost daughter herself. She is the central character around whom the story revolves.
There might be a mother figure. She could play a crucial role in the lost daughter's life, perhaps being the source of some of her inner conflicts. Their relationship would be a significant aspect of the story.
Maybe there are some friends or acquaintances that the lost daughter interacts with. These characters could help to reveal different sides of the lost daughter's personality, or they could be catalysts for certain events in her life. For example, a friend could encourage her to take a particular journey or make a life - changing decision.
Obviously Caius is one of the main characters. And his lost daughter would be another key figure, even if she might not be physically present throughout the story. There could also be characters who are friends or allies of Caius, like a wise old man who gives him advice on his search.
Since I haven't read the book, I can't say for sure. But they could be the lost boys and girls themselves, with each having their own distinct personalities and backstories.
In 'For a Lost Soldier' novel, perhaps there is a young boy or girl who forms a connection with the soldier. This character could bring out different sides of the soldier's personality. And of course, there may be other soldiers or military personnel who play important roles in the story, either as comrades or antagonists to the main soldier character.
Perhaps there are also some supporting characters like a wise old woman who gives the lost girls advice. Or a young boy who befriends them and helps them in some way. There could also be an antagonist, maybe someone who is trying to keep the girls lost or is causing the problems they are facing.
The main character in 'the lost weekend novel' is an individual who is deeply entrenched in the grips of alcoholism. He is at the center of the story, and his experiences, his highs and lows related to his drinking habit form the core of the narrative. There are likely other characters such as those in his social circle, perhaps a friend who tries to help him or a family member who is worried about his condition. However, to get a more comprehensive understanding of all the main characters, one would need to thoroughly read the novel as their roles and significance may be more nuanced and complex than what can be initially assumed.
Since I'm not familiar with the 'lost stars novel', the main characters could be individuals with different backgrounds and personalities. Maybe there's a misfit who doesn't fit into the norms of society, and a more conventional character who helps the misfit on their journey. There could also be a mentor - like figure who provides guidance to the other characters as they struggle with their 'lost' states.
I'm not sure without reading the novel specifically, but they are probably the lost girls themselves and maybe the people who are looking for them.
I'm not sure exactly as I haven't read the novel in detail. But it's likely the lost boys themselves are the main characters.
Since I'm not familiar with the book, the main characters could be various family members with different personalities and roles. There might be a rebellious teen who has run away from home, causing the family to be 'lost' in a sense, and the other family members are trying to bring this character back and restore the family harmony.
The main characters in the 'lost boys novel' are presumably the lost boys. These boys would be the focus of the story. They might have individual backstories that led to them being in the situation of being lost. There could also be side characters such as local inhabitants of the area where they are lost. These side characters could either be friendly and help the lost boys or be hostile and create more problems for them.