Main •
Ji Chang-wook as Park Tae-jung : A man who lived an ordinary life but was falsely accused of committing a heinous crime, and was sentenced to life. •
Doh Kyung-soo as An Yo-han : Tae-jung's benefactor in prison. •
Jo Yoon-su as No Eun-bi : Yong-sik's daughter. •
Lee Kwang-soo as Baek Do-kyoung : Yo-han's VIP client.
Supporting Guan Prison •
Yang Dong-geun as Yeo Deok-su : The most influential person in Guan Prison. • Kim Jae-chul as Yang Chul-hwan : A prison officer of Guan Prison. •
Eum Moon-suk as Do Gang-jae : A fellow inmate in Guan Prison, and the fierce rival of Deok-su. • Lee Jae-kyoon as Koo Ji-yong : Tae-jung's cellmate in Guan Prison. •
Lee Seo-hwan as Park Han-hee : The warden of Guan Prison.
Others • Kim Joong-hee as Kim Sang-rak : A public defender of Kim Sang-rak Law Office. •
Ahn Ji-ho as Park Tae-jin : Tae-jung's younger brother. • Kwon Da-ham as Woo-jong : Tae-jung's friend. •
Kim Jung-heon as Jung-soo : Tae-jung's friend. • Lee Suk-hyeong as Dae-hoon : Tae-jung's friend. • Han Ji-hyo as Lee Sun-ah : Eun-bi's roommate. • Son Jong-hak as Baek Sang-man : Do-kyoung's father and a sitting member of the National Assembly. •
Lim Hwa-young as So Hyun-jung : The boss of a hair salon, and the next manipulated target of Yo-han. • Lee Sung-woo as Hwang Il-guk : A corrupt detective of the Seoul Junggu Police Station. • Lee Hyun-jin as Ching Li : A Chinese killer working for Yo-han. • Kim Min as Yoo Seon-gyu : Do-kyoung's partner. • Do Hyun-jin as Han-byeol : Eun-bi's friend in Busan.
Special appearances •
Pyo Ye-jin as Song Su-ji : Tae-jung's girlfriend. • Lee Jong-hyun as a sports car driver • Lee Jae-won as a prosecutor •
Bae Na-ra as Woo Min-hyung : A killer working for Yo-han. • Jeong In-gi as Yo-han's nanny • Park Mi-hyun as Do-kyoung's mother ==Production==