Ghost Messengers are super-power agents from the underground world called the World of Death. The World of Death is a digitalized world with cutting-edge technologies that control and manage the life and death of all living things based on its elaborate systems. 
Our Ghost Messenger hero, Kang-lim, has been dispatched to the human world to capture the remaining ghosts who are refusing to go to the World of Death although it is their time. 
An accident occurs during his mission and Kang-lim gets captured in his own mobile phone. Little Kang-lim, a human boy who has extraordinary spiritual powers, finds the mobile phone and takes GhostMessenger Kang-lim out from the mobile phone. 
And the adventure begins. 
(Source: Anime World Network)

The dangerous underworld is policed by ghost messengers who use their shape-shifting cell phones to maintain order and go after bad guys. While hunting a dangerous spirit, Master Kang Rim accidentally gets trapped inside his cell phone. That cell phone falls into the hands of Little Kang Rim, a 12-year-old boy who lives with his grandfather, who owns an antique store. Little Kang Rim has the unique ability to see spirits, and he finds himself pulled into service to help Master Kang Rim.
 
With the help of Bari, Master Kang Rim’s commander, can LIttle Kang Rim set things right with the underworld?
 
(Source: VIKI, edited)

Grandfather