The Frog

Director

• 
  Mo Wan Il

Main Role

• 
  Kim Yoon Seok

  Jeon Yeong Ha

  Main Role
• 
  Yoon Kye Sang

  Koo Sang Jun

  Main Role
• 
  Go Min Si

  Yoo Seong A

  Main Role
• 
  Lee Jung Eun

  Yun Bo Min

  Main Role

Support Role

• 
  Ryu Hyun Kyung

  Seo Eun Gyeong [Sang Jun's wife]

  Support Role
• 
  Park Ji Hwan

  Park Jong Du [Sang Jun's friend / former gangster]

  Support Role
• 
  Park Chan Yeol

  Koo Gi Ho [Sang Jun's son]

  Support Role
• 
  Hong Ki Joon

  Ji Hyang Cheol [Serial killer]

  Support Role
• 
  Lee Nam Hee

  Park Yong Chae [Yeong Ha's friend, Momo Pension owner]

  Support Role
• 
  Lee Sung Wook

  Choi Gyeong Nam [Laundromat owner]

  Support Role
• 
  Nam Ji Woo

  Song Ji Su [Ui Seon's husband, Pediatric & adolescent clinic director]

  Support Role
• 
  Cha Mi Kyung

  Kim Gyeong Ok [Jong Du's mother]

  Support Role
• 
  Choi Jung Hoo

  Koo Gi Ho [Teen]

  Support Role
• 
  Jo Ah Ra

  Director Choi [Ara Gallery]

  Support Role
• 
  Kim Jong Tae

  Detective Kang

  Support Role
• 
  Ahn Sang Woo

  Choi Jeong Ho

  Support Role
• 
  Jo Eun Sol

  Kim Seon Tae

  Support Role
• 
  Lee Yoon Jae

  Yeom Dong Chan [Bo Min's husband, Joongmin Ilbo reporter]

  Support Role
• 
  Lee Ga Sub

  Yeom Dong Chan [Young]

  Support Role
• 
  Lee Moon Sik Support Role

Guest Role

• 
  Kim Won Suk

  [Police officer] (Ep. 6)

  Guest Role
• 
  Lee Do Guk

  Kim Hwang Seon (Ep. 8)

  Guest Role
• 
  Ha Yoon Kyoung

  Yun Bo Min [Young] (Ep. 1-5)

  Guest Role
• 
  Choi Yong Jin

  [Realtor] (Ep. 2-3)

  Guest Role
• 
  Park Seung Joon

  [Student bully] (Ep. 2-3)

  Guest Role
• 
  Kwak Min Seok

  Director Kim (Ep. 3)

  Guest Role
• 
  Kim Joo Ah

  [Song Ji Su's mom] (Ep. 3)

  Guest Role
• 
  Joo In Young

  [Restaurant owner] (Ep. 3)

  Guest Role
• 
  Min Eung Shik

  [Police chief] (Ep. 3)

  Guest Role
• 
  Myung Jae Hwan

  [Convenience store customer] (Ep. 3)

  Guest Role
• 
  Lee Su Hyung

  [Convenience store customer] (Ep. 3)

  Guest Role
• 
  Kim Sung Yong

  [Restaurant customer] (Ep. 3)

  Guest Role
• 
  Kim Sung Ryung

  Lee Seong Ran [Yeong Ha's wife] (Ep. 3, 8)

  Guest Role
• 
  Roh Yoon Seo

  Jeon Ui Seon [Yeong Ha's daughter] (Ep. 3-4, 7-8)

  Guest Role
• 
  Kook Joong Woong

  [Garden center owner] (Ep. 4)

  Guest Role
• 
  Shin Hee Gook

  [Computer technician] (Ep. 4)

  Guest Role
• 
  Han Sang Chul

  [Mover] (Ep. 4)

  Guest Role
• 
  Seol Yu Jin

  [Pharmacist] (Ep. 4, 7)

  Guest Role
• 
  Jang Seung Jo

  Ha Jae Sik [Seong A's ex-husband] (Ep. 4, 7-8)

  Guest Role
• 
  Shin Na Ra

  [Renter] (Ep. 5)

  Guest Role
• 
  Oh Jin Kyoung

  [Renter] (Ep. 5)

  Guest Role
• 
  Byun Jung Hee

  [Ji Hyang Cheol's mom] (Ep. 5-6)

  Guest Role
• 
  Jeon Ah Hee

  [Nurse] (Ep. 6)

  Guest Role
• 
  Kim Won Seok

  [Police officer] (Ep. 6)

  Guest Role
• 
  Im Too Chul

  [Prison guard] (Ep. 6)

  Guest Role
• 
  Kim Jin Bok

  [Prison guard] (Ep. 6)

  Guest Role
• 
  Oh Hae Joo

  [Nurse] (Ep. 7)

  Guest Role
• 
  Hong Suk Bin

  [Chinese restaurant owner] (Ep. 7)

  Guest Role
• 
  Lee Seung Chul

  Director Yoo [Seong A's father] (Ep. 7-8)

  Guest Role
• 
  Lee Seon Joo

  [Park Yong Chae's wife] (Ep. 8)

  Guest Role
• 
  Kim Sang Il

  [Lawyer] (Ep. 8)

  Guest Role
• 
  Choi E Jun

  [Yong Chae's grandson] (Ep. 8)

  Guest Role
• 
  Baek Kil Sung

  [Detective captain] (Ep. 8)

  Guest Role
• 
  Cho Yeo Jun

  Ha Si Hyeon [Ha Jae Sik's son & Seong A's stepson]

  Guest Role
• 
  Kang Myoung Soo

  [Demolition worker]

  Guest Role
• 
  Lim Su Hwan

  [Police officer] (Ep. 1-2)

  Guest Role
• 
  Jeon Seong A

  [Student's mother] (Ep. 2)

  Guest Role