Hwang Jae-yeol

as Detective Kim

as Citizen

as Detective Park (12 episodes)

as Homeroom teacher (2 episodes)

as Mr. Park (1 episode)

as Choi

as Sang Hun [Convenience Store Owner from North Korea] (12 episodes)

as Detective

as Jung Jae Min (1 episode)

as Park Dong Chan (12 episodes)

as Detective Ki-won (1 episode)

as Jung Hyun-wo's Father (2 episodes)

as Detective Jung (12 episodes), as Chung Yu Cheol

as Detective Song (16 episodes)

as [Detective] (1 episode)

as Obese (2 episodes)

as Man-cheol

as Mr. Kim (3 episodes)

as Control Team Leader #1

as Jeong Du-man (Detective) (4 episodes)

as Gap-doo

as Kim Yoo-Chul [Detective] (12 episodes)

as Hong-gyu

as Ki Dong Su (3 episodes)

as Patient's Son (1 episode)