Yoo Tae-woong

as Kang Young-woong (100 episodes)

as Lee Min-Tae (104 episodes)

as Cha Ho-chul (1 episode)

as Jo Dong-Man (103 episodes)

as Han Jung-sik (16 episodes)

as Director Kim [Seung Joon's secretary] (1 episode)

as Hwang Pil Young [Black Ops Team Leader] (2 episodes)

as Motorcycle

as Shin Ma-jeok (24 episodes)

as Journalist Oh

as Sa Gi-Jin (120 episodes)

as Tae Ik's father (32 episodes)

as Jung Jae-Gyu (16 episodes)

as Northern investigative general

as Detective Kang

as Count Casanova (23 episodes)