Writer Yoo Hyun-Mi revealed that script writing process took 12 years.
Kim Mi-Soo (Yeo Jungmin)'s final on-screen role before her death at age 29 (or 31 by Korean age) on 5 January 2022.
The series is based on the memoirs of a man who escaped a political prison camp in North Korea.
In the period from March 26 to April 25, a total of 226,078 people signed an online petition to the Blue House demanding that production on Snowdrop be stopped.
On May 14, the Blue House issued an official response to the petition, rejecting the calls for the show's cancellation. The response stated that the Blue House did not intend to interfere in the production of Snowdrop, citing the protection of freedom of expression in South Korea's Broadcasting Law, which guarantees broadcasters' independence and prohibits extrajudicial regulation or interference.
Both Jung Hae-in (Im Soo-ho) and Yoo In-na (Kang Chung-Ya) were in the series Goblin (2016). Jung made a cameo as Choi Tae Hee, while Yoo stared as Sunny, one of the leads.