During the Joseon Dynasty, the Secret Royal Inspectors are the eyes and ears of the king. They travel the provinces undercover and listen to the plight of the common people, investigating abuses and corruption of government officials.

Kim Gwan-Chul used to work as an accountant, but now he works as a chief for a company. He is man who follows his principles and uses common sense. He also stands up for those in weaker positions.