- Park Bo-young (Do Bong-soon)
- Park Hyung-sik (Ahn Min-hyuk)
- Kim Ji-soo (In Guk-doo)
- Jun Seok-ho (Secretary Kong)
- Shim Hye-jin (Hwang Jin-i)
- Yoo Jae-myung (Do Chil-goo)
- Ahn Woo-yeon (Do Bong-gi)
- Kim Min-kyo (Agari)
- Yoon Ye-hee (Jung Mi-hwa)
- Kim Won-hae (Kim Kwang-bok / Oh Dol-pyo)
- Im Won-hee (Baek Tak)
- Kim Ki-moo (Hwang Hyun-dong)
- Seorina (Jo Hee-ji)
- Choi Won-myeong (Jang Kyung-tae)
- Jang Mi-kwan (Kim Jang-hyun)
- Lee Do-hyun (Jang Kwang-sook)
- Park Bo-Mi (Na Kyung-shim)
- Kim Young-Choon (Il-jin)
- Baek Su-ryeon (Grandmother Sun-shim)
- Yoon Young Joo (Min-hyuk's Stepmother)
- Kim Seong-beom (Ahn Dong-ha)
- Kim Won-suk (Detective Dotbogi)
- Shim Hoon-ki (Ahn Dong-suk)
- Lee Se-wook (Ahn Kyung-hwan)
- Choi Mu-in (Team Leader Yuk)
- Choi Hyung (Hee Raeng-i)
- Jun Byung-Chul (Lee U-jin)
- Choi Seung-hoon (Ahn Min-hyuk (young))
- Choi Hyun-Seo (Kim Ji-won)
- Ahn Chang-hwan (Jung Jun-tae)
- Yoo In-soo (Kang Gu)
- Kim Soo-yeon (Jae-soon's Mother)
- Kim Won-suk (Magnifying Glass)
- Yang Joo-ho (Knock Boy)
- Oh Soon-tae (Brown Bear)
- Heo Jung-Guk (Chairman Ahn Chul-do)
Strong Girl Bong-soon — S0E1
Episode: Special
Air Date: 2017-02-17
Runtime: 60 min
Overview
The special episode reveals behind-the-scenes stories from the actors during filming and a special commentary interview with the actors of the show.