On September 21, 2020, it was reported that Jang Na-ra and Jung Yong-hwa had received a proposal to pair in an occult drama, which they were considering positively; in November 2020, production company Monster Union confirmed the drama for the first half of 2021.

Kang Hong-seok and Baek Eun-hye had previously worked together on tvN's Wednesday-Thursday drama What's Wrong with Secretary Kim (2018) before reuniting in this series.

Ahn Gil-kang and Baek Ji-won had previously worked together on the KBS2 weekend drama Once Again (2020) before appearing together again in this series.

Ahn Gil-kang and Baek Eun-hye had already worked together on the SBS drama Kkotpiineun Season (Nokdu Flower), and Baek Eun-hye made a special appearance in that drama as well, making this their second collaboration.

Jung Yong-hwa won the Best Actor award in the Miniseries category at the 2021 KBS Drama Awards for his role in the series.

Lead actor Jung Yong-hwa also contributed to the soundtrack, performing the Part 1 OST track 'I Got Ya,' released on April 14, 2021, the same day the series premiered.

Lead actress Jang Na-ra also lent her voice to the soundtrack, singing the Part 4 OST track 'DAYDREAM (백일몽),' released on May 12, 2021.