The series is based on a web novel of the same name, first published in 2016 on KakaoPage.

The male lead role of Kwon Jung-rok was first offered to Jung Kyung-ho, who turned it down, before Lee Dong-wook was ultimately cast.

Lead stars Yoo In-na and Lee Dong-wook had previously worked together in the 2016 series Guardian: The Lonely and Great God, making this a reunion for the two actors.

Actor Shin Dong-wook was originally cast as prosecutor Kim Se-won, but stepped down from the series amid controversies surrounding fraud claims and a subsequent lawsuit, and was replaced by Lee Sang-woo.

The first script reading of the cast was held on November 27, 2018, at Studio Dragon's head office in Sangam-dong, Seoul, with filming starting that same month.