There could be a group of friends around the bad boy. They might be involved in the bet in some way, like trying to help the bad boy win or discouraging him from taking the bet. And for the other main character, there could be a best friend who gives advice on how to handle the bet and the bad boy. The bad boy himself might have some family members who are mentioned, like a single parent who is struggling to keep him in line, which could be part of the reason for his bad behavior. And the main character who bets with him might have siblings who also play a role in the story, for example, by teasing her about her bet with the bad boy.
The bet might involve academic performance. The school's bad boy is confident that he can ace a test without studying, and the other character bets that he can't. This leads to a series of interactions where the bad boy starts to realize the importance of education. Along the way, there could be some romantic tension between them. The bad boy might start to have feelings for the person who made the bet with him, and they face various obstacles like peer pressure and the bad boy's old habits.
Typically, you'll find a lot of tension and conflict. Maybe the bet leads to unexpected consequences that force the characters to grow and change. Also, there could be rivalries with other students and the struggle to keep the bet a secret.
Given the title, the two obvious main characters would be the bad boy and the princess. The bad boy might be a character with a troubled past, maybe from a broken family or has been in trouble with the law. The princess could be a girl who is seen as pure, beautiful, and has high social standing. There might also be supporting characters like the bad boy's friends or the princess's family members who play important roles in the story.
I don't know as I haven't read it. But it's likely to have the bad boy as one of the main characters.
Since I don't know the details of this 'the bad boy in suit novel', I can only assume. There would surely be the titular bad boy in a suit. There could also be a mentor - like figure, someone who tries to guide him towards the right path. And of course, there would probably be some rivals, either in his work or personal life, who add conflict to the story.
There might be his friends too. They join him in his adventures and sometimes egg him on in his naughty deeds. They all contribute to the wild and wacky situations that happen in the stories.
From the title, we can assume that the two main characters are the 'bad boy' who is the bully and the person who is being bullied. But without reading the novel, we can't know more about their personalities, backgrounds or any other characters that might be important in the story.
We don't really know without reading the book. However, based on the title, one main character is surely the 'bad boy'. The other might be the one he craves, who could be a girl or another character that has some sort of allure for him. There could also be secondary characters like friends or family members of the main two that play important roles in the story.
The main characters in 'the bad boy protects me novel' are surely the bad boy and the one he protects. The bad boy might have a name like Jake or Tyler, who is known for his rough behavior. The girl he protects could be named Lily or Emma. There may also be a teacher or a family member who becomes involved in the situation, but the core relationship is between the bad boy and the girl. Their different personalities and the situation of protection would form the basis of the story.
The main character is of course the bad boy himself. He's usually rebellious, doesn't follow the rules, and has a bit of an attitude. Then there's the good girl, who is often the object of the bad boy's affection. There are also the teachers, who are constantly trying to discipline the bad boy. And the jocks or popular kids who might pick on the bad boy or be in competition with him.