The Impossible Heir

Director

• 
  Min Yeon Hong

Screenwriter

• 
  Choi Won

Main Role

• 
  Lee Jae Wook

  Han Tae Oh

  Main Role
• 
  Lee Jun Young

  Kang In Ha

  Main Role
• 
  Hong Su Zu

  Na Hye Won

  Main Role

Support Role

• 
  Choi Jin Ho

  Kang Joong Mo

  Support Role
• 
  Kim Ho Jung

  Jang Geum Suk

  Support Role
• 
  Han Sang Jin

  Kang In Joo

  Support Role
• 
  Lee Ji Hoon

  Kang Seong Ju

  Support Role
• 
  Choi Hee Jin

  Kang Hee Joo

  Support Role
• 
  Ko Chang Seok

  Chae Dong Wook

  Support Role
• 
  Heo Nam Jun

  Ha Myung Jin

  Support Role
• 
  Jang Hyuk Jin

  Chu Hyeok Jin [Jung Mo's secretary]

  Support Role
• 
  Kim Young Joo

  Yoon Hyang Mi [Hye Won's mother]

  Support Role

Guest Role

• 
  Lee Kang Ji

  Heo Byung Sung (Ep. 1)

  Guest Role
• 
  Lee Si On

  Han Tae Ho [Child] (Ep. 1)

  Guest Role
• 
  Woo Hyun

  [Village chief] (Ep. 1)

  Guest Role
• 
  Byeon Gyeong Rok

  [Teaching assistant] (Ep. 1)

  Guest Role
• 
  Kang Hak Soo

  [Homeroom teacher] (Ep. 1)

  Guest Role
• 
  Choi Nam Uk

  [Convenience store owner] (Ep. 1)

  Guest Role
• 
  Lim Su Hyeon

  Ms. Jin (Ep. 2)

  Guest Role
• 
  Kim Sang Bo

  Seo Yeol (Ep. 2)

  Guest Role
• 
  Sung Ji Ru

  Boss Tak (Ep. 2)

  Guest Role
• 
  Yoon Se Woong

  Mr. Moon (Ep. 2)

  Guest Role
• 
  Ahn Dong Yeob

  Bong Man (Ep. 2)

  Guest Role
• 
  Seo Suk Gyu

  Secretary Lee (Ep. 2)

  Guest Role
• 
  Lee Kyung Oh

  Seo Won Hae (Ep. 3)

  Guest Role
• 
  Kim Soo Jung

  Kim Hyun Seok (Ep. 3)

  Guest Role
• 
  Lee Hwang Ui

  In Kyu Dong [Hospital director] (Ep. 3)

  Guest Role
• 
  Yoo Byung Sun

  [Reseacrher] (Ep. 3)

  Guest Role
• 
  Kim Hyuk Jong

  [Sun Dong’s aide] (Ep. 3)

  Guest Role
• 
  Kim Ji Na

  [Host club manager] (Ep. 3)

  Guest Role
• 
  Kwon Hyuk

  [In Ju's assistant] (Ep. 4)

  Guest Role
• 
  Shin Jun Chul

  [Stock market manager] (Ep. 4)

  Guest Role
• 
  Shin Hee Gook

  [Stock market staff] (Ep. 4)

  Guest Role
• 
  Jang Eun Seo

  [Kang Oh Securities staff] (Ep. 4)

  Guest Role
• 
  Yang Hee Woo

  [Kang Oh Securities staff] (Ep. 4)

  Guest Role
• 
  Richard Kim

  Jeong Jin Ho (Ep. 5)

  Guest Role
• 
  Jin Shi Won

  [Team leader] (Ep. 5)

  Guest Role
• 
  Kwon Tae Jin

  [In Joo’s friend] (Ep. 5)

  Guest Role
• 
  Jang Se Hwan

  [Doctor] (Ep. 6)

  Guest Role
• 
  Song Chang Gyu

  [Gambler] (Ep. 6)

  Guest Role
• 
  Ban Eun Se

  Park Jin Kyung (Ep. 7)

  Guest Role
• 
  Yun Ki Chang

  [Detective] (Ep. 7)

  Guest Role
• 
  Heo Seon Haeng

  [Judge] (Ep. 7-8)

  Guest Role
• 
  Lee Dong Soo

  [Lawyer] (Ep. 7-8)

  Guest Role
• 
  Jung Han Bin

  [Prosecutor] (Ep. 7-8)

  Guest Role
• 
  Kim Wang Do

  [Prison guard] (Ep. 7-8)

  Guest Role
• 
  Park Bin

  [Prison guard] (Ep. 8-9)

  Guest Role
• 
  Han Dae Gwan

  [Director] (Ep. 10)

  Guest Role
• 
  Kim Woo Jin

  [Cellphone technician] (Ep. 10)

  Guest Role
• 
  Im Yong Soon

  [Judge] (Ep. 10)

  Guest Role
• 
  Kaare Svejgaard Olsen

  James B. Olson (Ep. 10)

  Guest Role
• 
  Kim Tae Hoon

  [Prison guard] (Ep. 11)

  Guest Role
• 
  Jung Ho

  [Staff] (Ep. 11-12)

  Guest Role
• 
  Kim Jung Soo

  [Judge] (Ep. 12)

  Guest Role
• 
  Robin Deiana

  Amico

  Guest Role
• 
  Gong Yoo Rim

  Ma Ju Yi

  Guest Role
• 
  Lee Jang Won

  Chief Ma

  Guest Role
• 
  Choi Byung Mo

  Han Kil Su

  Guest Role
• 
  Jung Han Bit

  Shin Bo Na

  Guest Role
• 
  Lee Seo An

  Jung Ji Sun

  Guest Role
• 
  Yoon Jung Hoon

  Ko Hui Chan

  Guest Role
• 
  Kwon Tae Won

  Jo Sun Dong

  Guest Role
• 
  Lee Do Hyung

  Yang Ji Hoon

  Guest Role
• 
  Jang Ma Ru

  Sun Woo Wan

  Guest Role
• 
  Park Joong Geun

  Oh Gyeong Cheol

  Guest Role
• 
  Kim Woo Dam

  Jung Dong Myung

  Guest Role
• 
  Gu Hyun

  Kang In Ha [Child]

  Guest Role
• 
  Jung Hye Jin

  Seo Ji Sook [Tae Oh's mother]

  Guest Role
• 
  Kwak Yeong Seon

  Jeon Yeong Min (Ep. 3)

  Guest Role
• 
  Kang Do Yoon

  [Gang subordinate] (Ep. 8)

  Guest Role
• 
  Cho Myeong Gyun

  [Member of Tae O’s group]

  Guest Role

Unknown

• 
  Honey Chae Unknown
• 
  Seo Seung Hyun

  Hong Gyu

  Unknown