Generally, romance novels would involve the male and female protagonists, their intimate relationship, passersby, villains, or other characters in their intimate relationship. To be specific, the male and female protagonists were often important characters, and the love line between them was also one of the main plots. The passers-by in the intimate relationship might play a role in promoting the development of the plot or adding some suspense. The villain was an important background for the protagonists to face more challenges or crises. Other characters might provide help to the protagonist or provide other help.