- Hyun Bong-sik
- Â Detective Bok Ho-nam 20 episodes, 2021
- Jo Jae-yoon
- Â Daniel Lee 20 episodes, 2021
- Jung Ae-ri
- Â Choi Young Shin 20 episodes, 2021
- Kwon Hwa-woon
- Â Sung Yo-han 20 episodes, 2021
- Ahn Jae-wook
- Â Han Seo Jun 20 episodes, 2021
- Kim Jung-nan
- Â Sung Ji Eun 20 episodes, 2021
- Kim Kang-hoon
- Â Jae Hoon 20 episodes, 2021
- Ahn Nae-sang
- Â Detective Park Du Seok 20 episodes, 2021
- Lee Seung-gi
- Â Jung Ba Reum 19 episodes, 2021
- Lee Hee-joon
- Â Go Moo Chi 19 episodes, 2021
- Park Ju-hyun
- Â Oh Bong-yi 19 episodes, 2021
- Kyung Soo-jin
- Â Choi Hong-joo 19 episodes, 2021
- Pyo Ji-hoon
- Â Detective Shin Sang 19 episodes, 2021
- Woo Ji-hyeon
- Â Koo Dong Koo 19 episodes, 2021
- Kang Mal-geum
- Â Ba Reum's Aunt / ... 19 episodes, 2021
- Yoon Seo-hyun
- Â Detective Kang Ki Hyeok 19 episodes, 2021
- Kim Min-Soo
- Â Detective Lee Min Soo 19 episodes, 2021
- Chun Jung-ha
- Â Na Chi Kook's mother 8 episodes, 2021
- Seo-Joon Lee
- Â Na Chi Kook 8 episodes, 2021
- Jeong Eun-pyo
- Â Kang Duk-soo 7 episodes, 2021
- Kwon Hyuk-soo
- Â Doctor 7 episodes, 2021
- Kim Young-jae
- Â Go Moo Won 6 episodes, 2021
- Baek Jae-Woo
- Â Song Soo-ho (young) 6 episodes, 2021
- Lee Do-Hyung
- Â Ba Reum's uncle 5 episodes, 2021
- Kim Ha-eon
- Â Kim Han-gook 5 episodes, 2021
- Cherish Maningat
- Â Kim Han Kook's mother 5 episodes, 2021
- Kim Young-ok
- Â Bong Yi's grandmother 5 episodes, 2021
- Park So-yi
- Â Kim Hyun-soo 5 episodes, 2021
- Jung Suk-yong
- Â Woo Jae Pil 5 episodes, 2021
- Kim Min-kyeong
- Â Song Soo Jung's mother 5 episodes, 2021
- Lee Chae-Hyun
- Â Hoon Suk 4 episodes, 2021
- Hong Eun-jeong
- Â Seul Ki 3 episodes, 2021
- Hwang Se-won
- Â Kim Da Seul 3 episodes, 2021
- Song Jae-hee
- Â Attorney Woo Hyung Chul 3 episodes, 2021
- Choi Sol-Hee
- Â Yu Na's mother 3 episodes, 2021
- Kim Moon-ho
- Â Lee Jae Shik 3 episodes, 2021
- Kwon Ye-Eun
- Â Yu Na 3 episodes, 2021
- Shin Yun-sook
- Â Kang Duk Soo's mother 3 episodes, 2021
- Jang Yong-Chul
- Â Kim Bong Cheol 3 episodes, 2021
- Son Woo-Hyun
- Â Kim Joon Sung 3 episodes, 2021
- Joo Ye-rim
- Â Oh Bong Yi (young) 3 episodes, 2021
- Song Boo-gun
- Â Song Soo Ho 3 episodes, 2021
- Yu Ha-bok
- Â Shin Sung Min 3 episodes, 2021
- Jo Yeon-ho
- Â Go Moo Won (young) 3 episodes, 2021
- Park Gi-ryoong
- Â OBN News Chief 2 episodes, 2021
- Park Eun-yeong
- Â Staffing Agency Woman 2 episodes, 2021
- Garrison Michael Farquharson-Keener
- Â Doctor Fallon 2 episodes, 2021
- Song In-Seob
- Â Prison Doctor 2 episodes, 2021
- Bo Ra-na
- Â Hostess bar manager 2 episodes, 2021
- Kang Ro-chae
- Â Park Hye Won 2 episodes, 2021
- Kim Sung-kyung
- Â Fact Check host 2 episodes, 2021
- Kwak Min-ho
- Â Prisoner 2 episodes, 2021
- Choi Yoon-Bum
- Â Officer Nam 2 episodes, 2021
- Jo Wan-gi
- Â Reporter Yang 2 episodes, 2021
- Seon Ah Rin
- Â Jo Mi-Jung 2 episodes, 2021
- Byun Yoon-Jeong
- Â Mrs. Oh 2 episodes, 2021
- Bae Sung-il
- Â Detective Interviewing Jae Hoon 2 episodes, 2021
- Kim Young-joo
- Â Sherlock Hong Ju Staff 2 episodes, 2021
- Kim Woo-jin
- Â Police Officer Kim 2 episodes, 2021
- Shim Yu-Seung
- Â Sherlock Hong Ju staff 2 episodes, 2021
- Shin Ha-young
- Â Song Soo Jung 2 episodes, 2021
- Lee Eon-jeong
- Â Ba Reum's mother 2 episodes, 2021
- Seo Woo-Jin
- Â Jae Hoon (5 Years old) 2 episodes, 2021
- Song Min-jae
- Â Go Moo Chi (Child) 2 episodes, 2021
- Paul Battle
- Â Dr. John 1 episode, 2021
- Kim Bi-bi
- Â Nun 1 episode, 2021
- Kim Ah-Ram
- Â Sung Ji Eun's employee 1 episode, 2021
- Yang Ha-yoon
- Â Min Jung 1 episode, 2021
- Kim Ha-neul
- Â Jung Soo Jin 1 episode, 2021
- Seo Dong-hyun
- Â Go Moo Chi (teen) 1 episode, 2021
- Brad Curtin
- Â Doctor Gary 1 episode, 2021
- Kim Yeon Hee
- Â Grocery Store Employee 1 episode, 2021
- Park Hyun-Jeong
- Â Kim Young Hee 1 episode, 2021
- Park Hye-Na
- Â Byun Soon Young 1 episode, 2021
- Lee Jae-eun
- Â Koo Dong Koo's Mom 1 episode, 2021
- Kim Hyo-gyeong
- Â Byun Min Ji 1 episode, 2021
- Ko Eun-Bi
- Â Angela (child) 1 episode, 2021
- Jang Jae-kwon
- Â Second Male Talk Show Guest 1 episode, 2021
- Shin Hee-Gook
- Â Koo Dong Koo's friend 1 episode, 2021
- Park Jae-wan
- Â Police Commissioner 1 episode, 2021
- Kim Joo-a
- Â Orphanage Employee 1 episode, 2021
- Kim Ji-su
- Â Park Hye Won's friend 1 episode, 2021
- Oh Ji-Young
- Â Female Talk Show Guest 1 episode, 2021
- Yoon-jae Ji
- Â Kim Byung Tae 1 episode, 2021
- Kim Ro-sa
- Â Student's Mother 1 episode, 2021
- Seo Min-Seong
- Â Prison Officer Kim 1 episode, 2021
- Hackjin Mun
- Â Parole officer 1 episode, 2021
- Kim Soo-In
- Â Mystery Girl 1 episode, 2021
- Oh Min-Joon
- Â Bully 1 episode, 2021
- Min Jung-Sup
- Â Han Soo Chul 1 episode, 2021
- Kim Jung-han
- Â Man on bus stop 1 episode, 2021
- Kim Young-sun
- Â Science teacher 1 episode, 2021
- Go Na-eun
- Â Jennifer 1 episode, 2021
- Eoin Stanley
- Â Doctor 1 episode, 2021
- Uhm Hye Soo
- Â Police Officer 1 episode, 2021
- Yoo Yeon
- Â Woo Hyung Chul's mother 1 episode, 2021
- Jung Nan-Hee
- Â Teacher 1 episode, 2021
- Kang Suk-won
- Â Male Talk Show Guest 1 episode, 2021
- Choi Yi-Sun
- Â Motorcycle Deliveryman 1 episode, 2021
- Ha Seung-Youn
- Â Angela 1 episode, 2021
- Seo Yoon-hyuk
- Â Woo Hyung Chul (young) 1 episode, 2021
- Shin Soo-Hyeon
- Â Michaela 1 episode, 2021
- Kim Sung-joon
- Â Myung Ko Nam 1 episode, 2021
- Lee Yong-nyeo
- Â Grandmother 1 episode, 2021
- Yoo-Yong
- Â Sisters Killer 1 episode, 2021
- Im Yu-Ran
- Â Witness 1 episode, 2021
- Seo Jung-yeon
- Â Go Moo Chi's mother 1 episode, 2021
- Kim Dong-ha
- Â Jae Min 1 episode, 2021
- Kim Mi-Hye
- Â Jae Hoon's teacher 1 episode, 2021
- Jang Eui-don
- Â Attorney Hwang 1 episode, 2021
- Lee Ja-ryeong
- Â Kim Woo Seon 1 episode, 2021
- Jung Kang-hee
- Â Go Moo Chi's father 1 episode, 2021
- Kang Moon-kyung
- Â President 1 episode, 2021
- Min Eung-shik
- Â Shin Jae Hyung 1 episode, 2021
- Kim Gyeol
- Â Jae Hoon's father 1 episode, 2021
- Bok-Sung Yoon
- Â Jung Joong Suk 1 episode, 2021
- Ahn Seo-Yeon
- Â Jae Hee 1 episode, 2021
- Chang-Hyun Han
- Â Government Employee 1 episode, 2021
- Kang Chan-yang
- Â Nurse 1 episode, 2021
- Sung Chan-Ho
- Â Government official 1 episode, 2021
- Park Yong
- Â Kim Ji-Wan 1 episode, 2021
- Sin Dong-yup
- Â Self (uncredited) 1 episode, 2021
