The idea for Masquerade developed from the true story of missing records totalling 15 days from the Annals of the Joseon Dynasty. Knowing that the king was kind, but paranoid, the staff constructed this idea as something that could have happened during that undocumented time.
The second most successful film of 2012 in South Korea, following Les Braqueurs (2012) and preceding Avengers (2012).
Kang Woo-suk was originally set to direct in early 2011, with Jeong Jae-yeong starring as Gwang-hae & Ha-seon and Yoo Joon-sang as Heo Gyun but due to disagreements with the production company, Kang dropped out of project and Choo Chang-min came on board to direct in November 2011.