Main •
Jung Kyung-ho as Noh Moo-jin (a labor attorney who can see spirits) •
Tang Jun-sang as Bo Sal (Buddha) •
Kyung Soo-jin as Na Mi-joo (the estranged wife of Moo-jin, Hee-joo's older sister)
Supporting •
Park Soo-oh as Lee Min-wook (Ep. 2 - Student factory worker died in a tragic accident in an illegal factory) •
Hwang Bo-reum-byeol as Jo Eun-young (Ep. 3, 4 - Rookie nurse committed suicide in a hospital as she was unjustly blamed for causing a patient's death) •
Kang Ae-shim as Kim Young-sook (Ep. 5, 6 – Janitor who died of a heart attack while studying for exams inhumanely imposed on janitors by the employer)
Guest appearances •
Kim Dae-myung as Jung-min (Ep. 1 - a close friend of Moo-jin, who advises Moo-jin to use his retirement money to buy Bit-coins) •
Jun Gook-hyang as Yang Eun-ja (Ep. 1, 5, 6 - Moo-jin's mother, a cleaning worker) •
Kim Kang-hyun as Chul-yong (Ep. 1 - Head of the HR Department at Moo-jin's company) •
Yun Je-wook as Lee Jae-sung (Ep. 1, 2 - Director of an illegal factory) •
Kang Hye-won as Lee Yu-jin (Ep. 2, 8 - Social affairs reporter and former colleague of Gyeon-woo) •
Kim Gwi-sun as Taehyeop Steel President (Ep. 2 - Owner of an illegal factory) •
Anupam Tripathi as Nimal (Ep. 2 - Factory foreign worker) •
Lee Mi-do (Ep. 3 - Shaman who gives Moo-jin a exorcism course) •
Song Young-gyu (Ep. 3 - Church priest whom Moo-jin visits during the exorcism course) •
Ok Ja-yeon as Lee Su-jung (Ep. 3, 4 - Senior nurse who has been under stress and didn't protect Eun-young and felt guilty about it) •
Shin Joo-hyup as Park Hyun-woo (Ep. 3, 4 - Resident doctor incorrectly prescribed KCL and blamed it on Eun-young) •
Lee Chang-min as Jung-yup (Ep. 4 - Eun-young's boyfriend) •
Jin Seon-kyu as Noh Woo-jin (Ep. 5, 10 - Moo-jin's elder brother, a diligent construction worker) •
Ahn Nae-sang as Oh Jang-geun (Ep. 5, 6 – Janitor working in a university) •
Choi Jung-in as Hye-jung (Ep. 7 - Supermarket manager tries to over up Yoon-jae's accident by refuting the claim of a poor working environment) •
Choi Moo-sung as Kim Myung-an (Ep. 8, 9, 10 - CEO of the Myung-eum Construction, villain in the biggest industrial accident) •
Lim Chul-hyung as CEO Choi (Ep. 8, 9 - CEO of the Bukguk Warehouse responsible for the fire) •
Moon So-ri as Moon Jung-eun (Ep. 9, 10 - Big-time National Assembly member) •
Park Hae-il (Ep. 10 - Special voice appearance at the end, mysteriously calling Moo-jin, "Excuse me. Mr. Noh Moo-jin, the labor attorney..") ==Production==