This show was actually produced by the Joongang Tongyang Broadcasting Company (JTBC), a South Korean nationwide pay television network. It is being aired separately on Disney+ outside South Korea.
Kim Mi Soo was a support player in the show.
It is an interesting story
Snowdrop takes place in 1987, a pivotal year in South Korean history that included the June 1987 Democracy Movement, a mass protest movement with the purpose of forcing the dictatorship in South Korea to hold fair elections, and the resulting December 1987 democratic elections, which led to the end of the authoritarian Fifth Republic of Korea and the establishment of the democratic Sixth Republic of Korea.
Snowdrop is set in November and December 1987. Lim Soo-ho (Jung Hae-in) plays a graduate student who is discovered covered in blood by Eun Young-ro (Jisoo), a female university student. The girl hides him from the government in her dorm room at her women’s university. However, it is revealed that Soo-ho is not who he appears to be. Against the backdrop of political upheaval, the pair’s story unfolds and the two develop a romantic relationship.
Based on the memoirs of a man who escaped a political prison camp in North Korea, writer Yoo Hyun-mi had been planning the series for twelve years.
The show has caused some controversy in South Korea.
https://en.wikipedia.org/wiki/Snowdrop_(South_Korean_TV_series)
I meant to note that filming is complete and the show has aired 7 of 16 episodes in South Korea. The wiki page makes no mention on Kim Mi Soo.
The only show she is the main character in is a 2019 movie that has not been released. So she was not a big star.