Typically, the main characters would be Sora and Shiro, just like in the main 'No Game No Life' story. They are likely to be involved in the side stories as well, using their wits and gaming skills.
I'm not sure as we don't have enough information. But it could be the safari guide who leads the players through the game world.
The main characters are Tony and Maria. Tony is a member of the Jets gang, and Maria is related to the Sharks gang. Their love is the central focus of the story.
I'm not entirely sure who the main characters are in the side story. It could be some characters who were secondary in the main Life Is Strange 2 but get more focus here.
Since I don't know the game well, I can't name the main characters. But they could be ordinary people thrown into extraordinary situations within the 13 - day time frame.
Since we don't really know the details of 'the good life game story', the main characters could be diverse. They might be characters with different skills and personalities. For instance, there could be a creative character who is good at art and design in the game world, and another character who is more into physical activities like sports or exploration. Or perhaps there are characters representing different generations, like a young and ambitious character and an older, wiser one.
There are often new characters introduced in side stories. For example, Dunk and Egg are significant ones. Dunk is a hedge knight with his own code of honor, and Egg is actually Aegon V Targaryen in disguise. Their adventures in the side story add more depth to the complex world of Westeros, showing different aspects of chivalry, power struggles, and the life of the common folk compared to the main series.
The villainess herself is a main character. Her character development from being a typical villainess in the original concept to something more complex is a central focus.
Since we don't have much information about this specific light novel, the main characters could be a diverse group. Maybe there's a protagonist who is trying to survive in the 'jinrou game' while dealing with the challenges from the 'beast side'. There might also be antagonists who are using the beast - like features or rules of the game to their advantage, trying to eliminate other players.
I'm not sure exactly who the main characters will be in the side story. But it's likely that the main character from the original '19th life' story will play an important role.
There is the male protagonist who is often at the center of the story. He interacts with a variety of monster girls. Each monster girl has her own distinct personality. For example, there is a mermaid - like monster girl who is very gentle and kind.