Kim Do-Ki (Lee Je-Hoon) graduated from the Naval Academy and became an UDT (underwater demolition team) Official. His mother was murdered by a serial killer and his life changed afterwards.
Kim Do-Ki is now a deluxe taxi driver and works for Rainbow Taxi Company. The company is not just an ordinary taxi company. The company offers a special “revenge-call” service. If clients ask them to take revenge, Kim Do-Ki and his co-workers will perform the service.