Yang Kookil began his writing career by winning the grand prize at the Underfree Horror Contest with his 2001 horror story The Steel Tower Is Watching. He went on to be named the Best New Artist and Best Digital Writer by Moonhak Segye. He also won the Gangwon Ilbo Shinchun Literary Prize in the fairy tale category. He has published in full-length novels such as Written by a Ghost, Fire Girl Arena, and Devil Spirit, as well as the horror collections Horror Fiction and The Hell Doll.