Secretly Greatly

As a North Korean secret agent, Ryu-hwan infiltrates into the South. After 2 years of playing the role of the village idiot, fellow elite spies Hae-rang, posed as a rock star and Hae-jin, posed as a high school student, are dispatched to the same town as him. With the drastic power shift in the North, the three spies finally receive the mission, but it's nothing like their expectations.