Seungyeon, a frustrated writer, wakes up one day in the body of the father of a character from a BL novel written by his sister. Woojin, who saved his life from imminent danger, is the father of the obsessed protagonist who pursues the novel's love interest. Seungyeon discovers that he and Woojin are the parents of the main BL characters.

Seungyeon tries to follow the original plot, but soon realizes something is wrong. His relationship with Woojin becomes increasingly intimate and different from what he expected. Will Seungyeon be able to return to his normal life, or will he be trapped in his sister's romance forever?