Main •
Jung Woo as Yuk Dong-joo: an aspiring writer who makes a living by working part-time jobs while writing novels. •
Park Yu-rim as Park Hyun-soo: a homicide detective. •
Oh Man-seok as Kai: a mysterious man.
Supporting People around Dong-joo and Kang-san •
Kang Mal-geum as Chae Woo-jung: CEO of a book café. • Seo Jae-hee as Kang Hye-kyung: CEO of a high-class social café. •
So Hee-jung as Cha Young-sook: Dong-joo's mother. • Jo Bok-rae as Jung Yong-dae: Dong-joo's best friend who is a police officer. •
Yoon Na-moo as Yuk Chan-seong: Dong-joo's father.
Homicide Investigation Team 3 •
Ahn Nae-sang as Lee Byung-man: a homicide detective and inspector. •
Choi Deok-moon as Team Leader Oh: leader of Homicide Investigation Team 3.
Others •
Lee Sung-wook as Lee Tae-man: chairman of Taekang Group. • Kim Dong-hun as young Lee Tae-man • Choi Gwang-il as Byun Jong-il: a member of the national assembly. • Song Jae-ryong as Shin Gyeong-chul: a world-renowned film director. • Lee Do-hyung as Na Sang-woo: the son of a professor's family who disappeared nine years ago. • as Jeon Doo-hyun: a victim of a murder case. •
Son Ji-yoon as Myung-seok's colleague who is the editor-in-chief of the publishing company. • Shin Yi-june as Kim Yeon-hee: a high school student. •
Woo Hyun as Noh Myung-nam • Lee Han-wi as a school principal • Baek Seung-cheol ==Production==