Adapted from the popular online novel of the same name, it tells the story of Yoon Hyun-woo (Song Joong-ki), a secretary who manages a chaebol family, who is wrongly accused of embezzlement and is killed by the chaebol family. Yoon Hyun-woo is reborn as Chen Daojun, the youngest son of the chaebol family, and takes revenge while growing up with a new identity.