Joo Joong-won is a fictional character from the popular South Korean television drama series, Master's Sun. He is portrayed by actor So Ji-sub and is known for his cold and aloof demeanor. As the CEO of a successful company, he becomes entangled in a supernatural romance with the female lead, Tae Gong-shil, who can see ghosts. Throughout the series, Joo Joong-won evolves from a self-centered businessman to a more compassionate individual. His character development is central to the plot, as he learns to confront his fears and embrace love, ultimately forming a deep bond with Tae Gong-shil.