Lee Jun-hyeok (actor, born 1972)

Hwang Myeong-su / Hwang Deok-gu

Go Kyung-se

Noh Seong-gil: the king's chief eunuch.

Kang Nam-il: Ma Hee-ja's new partner and gambler

Master Jang: a former police officer.

A merchant

Chief Hong

Professor Park Bo-gum

Kim Jung-guk

Banjang Yu (ep. 6)

Chun-bae

Yang Joon-seok, a father at Serenity Birthcare Center who gives advice to Do-yoon (Ep. 2 & 5)

Department Chief Yeom / Lord Kim Jin

Seo Ji-tae, (40 years old) Inspector homicide detective. He is a father of twins

Go Se-hyeok, scout team leader.

Yeon Joon-suk, the CEO of Yeon Entertainment, Jin-shim's agency, who discovered and made her an actress.

Yoo Dae-yong, head of the metropolitan investigation team.

Choi Hang-seo

A director with amnesia (ep. 1)

Go Young-cheol

A CEO trying to steal a yongdoli mask patent (Ep. 1)

Chief Gong

Kim Pil-doo (39 years old)

Park Bok-eun

Director Lee Hyuk-joon

Jo Han-woo

Hong Yong-gae

Boss's subordinate

Bae Dae-hoon, the first recruit and senior member of Crime Squad Team One, Kang Sang-chul's buddy, senior of Shin Yeo-ok at Central Division police. He is good at explaining scenarios and knows many resource persons.

Hong Dae-hong, Moo-hyul's martial arts teacher

Detective Na

Criminal (ep. 1)

Ha Dong-geun, P.E. teacher

Han Jung-soo

Sang-beom