There might be some relationship between the male protagonist and the three girls, depending on the plot and setting of the novel. Generally speaking, there might be some special connection between the male lead and the three girls, such as they used to be classmates, neighbors, friends, and so on. Or the male lead might be the three girls 'relatives, friends, teachers, employers, and so on. In the novel, the relationship between the male protagonist and the three girls could be very complicated, involving family, friendship, love, betrayal, redemption, and so on. The readers could design and construct the story between the male protagonist and the three girls according to their own preferences and imaginations.