100 Days of Deception: Secret Document

100 Days of Deception: Secret Document is a special tvN variety show spin-off that serves as a prologue to the network's 20th-anniversary historical spy drama, 100 Days of Deception. The main cast members are transported into a 1930s-themed Japanese Government-General set. Under heavy security, they must crack hidden clues and execute an espionage mission to retrieve a "secret document".