Kim Eun-young (F, 48) Inspector (Team Leader or Task Force Chief) - Brownish-black hair - (Wife of Oh Jeong-taek) (Senior to Senior Superintendent Lee Da-hee, formerly Narcotics) (Biological mother of Oh Seung-yoon) [She knows her biological son, Oh Seung-yoon, was sent for adoption at age 5 to a new family living in Incheon. Originally from Mokpo, Jeonnam. Oh Seung-yoon is a 4th-year detective at the Jeonnam Agency, transferred from Incheon. He has no idea she is his mother. They work in the same field. She finds herself constantly concerned about him after meeting him by chance.] Oh Jeong-taek (M, 49) Inspector - Brown hair - (Husband of Kim Eun-young) (Senior to Commissioner Kang Dae-hyeop, formerly Organized Crime Investigation) (Biological father of Oh Seung-yoon) [His biological son, Oh Seung-yoon, whom he gave up for adoption at age 5, is now a 4th-year detective. His son's appearance and eyes slightly resemble his own.] Lee Ji-hye (F, 35) Lieutenant (Squad Leader) - Purple hair - (Mother of Senior Superintendent Lee Da-hee) Kim Hyun-woo (M, 33) Lieutenant - Reddish-brown hair - (Husband of Seo Seung-hee) Lee Seul-i (F, 30) Sergeant (Wife of Yoo Ji-ho) Yang Hyeon-jong (M, 29) Corporal Song Yeon-mi (F, 32) Sergeant Kang Young-tae (M, 28) Corporal Lee Seok-hyeon (M, 30) Sergeant (Husband and childhood friend of Lee So-young) Lee Ha-yeon (F, 29) Corporal Lee Jae-seong (M, 29) Corporal Go Eun-min (F, 28) Corporal - Pink hair - Park Hyeon-gyu (M, 29) Corporal Lee Min-ho (M, 31) Sergeant - Black hair, Gyle cut - Yoo Hyeon-jin (F, 27) Corporal Park Cheol-min (M, 28) Corporal Kim Ji-min (F, 30) Sergeant Park Yong-jin (M, 27) Corporal Lee Yeon-hee (F, 26) Officer Kim Yong-min (M, 26) Officer Yoon Bo-mi (F, 25) Officer Choi Tae-hoon (M, 25) Officer

Yoo Ji-ho (M, 32) Lieutenant (Violent Crimes Team Leader) - Lime hair - (Husband of Lee Seul-i) Kim Yeon-jae (F, 29) Corporal - Yellow hair - Oh Seung-yoon (M, 28) Corporal (4th-year veteran detective) - Brown hair - (Childhood friend of Kim Min-seo) [Since childhood, his only dream was to become a police officer. After starting at the Guwol Precinct in Incheon as a 25-year-old officer, he was transferred to the Jeonnam Agency where he has served as a detective for 4 years. His biological parents are Kim Eun-young and Oh Jeong-taek. He is called a veteran detective who has built up experience through missions and stakeouts.] Kim Min-seo (F, 28) Corporal - Red hair - (Childhood friend of Oh Seung-yoon) [Started at the Guwol Precinct in Incheon as a 25-year-old officer and transferred to the Jeonnam Agency, now in her 4th year in the Detective Division.] Kim Yong-cheol (M, 29) Corporal Seo Ye-eun (F, 28) Corporal (Girlfriend of Kim Jung-min) Lee Myeong-hak (M, 28) Corporal Yoo Jin-hee (F, 27) Officer Lee So-young (F, 30) Sergeant (Assistant Team Leader) - Blue hair - (Wife and childhood friend of Lee Seok-hyeon) Kim Hee-chul (M, 28) Corporal Lee Yoon-young (F, 26) Officer Kang Ho-dong (M, 27) Officer (Action-oriented detective) Kim Tae-won (M, 26) Officer Park Ye-jin (F, 25) Officer Lee Su-geun (M, 25) Officer

Lee Young-ho (M, 41) Inspector (Cyber Crime Division Chief or Team Leader) - White-khaki hair - Park Tae-seong (M, 30) Sergeant (Senior Agent) - Yellow hair - Seo Seung-hee (F, 33) Lieutenant (Assistant Team Leader and Investigative Officer) - Orange hair in a ponytail - (Wife of Kim Hyun-woo) Lee Tae-min (M, 28) Corporal Yoo Seong-min (M, 25) Officer (Youngest white-hat hacker/analyst) Kim Jung-min (M, 27) Officer (Boyfriend of Seo Ye-eun) Lee Ha-na (F, 29) Sergeant Shin Mi-young (F, 28) Corporal - Short green hair - Park Su-jeong (F, 27) Corporal - Short orange hair - Kim Mi-jin (F, 25) Officer (Youngest investigator)

Kang Dae-hyeop (M, 65) Commissioner (Jeonnam Provincial Police Chief) - Grey-black hair - (Junior to Oh Jeong-taek in the past during organized crime investigations) Lee Da-hee (F, 54) Senior Superintendent (Chief of Public Safety Information & Foreign Affairs or Inspector General) - Brown-khaki hair - (Daughter of Lee Ji-hye) (Junior to Kim Eun-young) Choi Hyeon-bin (M, 52) Superintendent (Provincial Investigation Division Chief or Detective Division Chief) Park Hye-ran (F, 51) Superintendent (Provincial Planning & Budget Chief or National Security Investigation Chief) Jung Jin-woo (M, 55) Senior Superintendent (Deputy Chief of Provincial Police or Investigation Bureau Chief)