Ghost Messengers are super-powered agents from the underground realm known as the World of Death. This is a digitized world featuring advanced technologies that regulate and manage the life and death of all living beings through its complex systems. Our protagonist, Ghost Messenger Kang-lim, has been sent to the human world to apprehend lingering ghosts who refuse to enter the World of Death despite it being their time. During his mission, an accident occurs, and Kang-lim becomes trapped inside his own mobile phone. Little Kang-lim, a human boy with exceptional spiritual abilities, discovers the phone and releases Ghost Messenger Kang-lim from it. And the adventure begins.