I'm afraid I don't have any information about the main characters in the 'man o salwa novel'. If you can get hold of a copy of the novel, reading the first few chapters usually gives a good indication of who the main characters are. They are often the ones whose actions and decisions drive the story forward and are described in more detail compared to other characters.
As I haven't read the 'man o salwa novel', I can only guess. Maybe the man and Salwa are the main characters. But there could also be other important characters that play significant roles in the story, like their friends or family members who might be involved in the plot development and influence the relationship between the man and Salwa.
Since I don't know the 'man o salwa novel' well, I can't tell you the main characters for sure.