Mr. Plankton

Composer

• 
  Kim Tae Seong

Director

• 
  Hong Jong Chan

Screenwriter

• 
  Jo Yong

Main Role

• 
  Woo Do Hwan

  Hae Jo

  Main Role
• 
  Lee You Mi

  Cho Jae Mi

  Main Role
• 
  Oh Jung Se

  Eo Heung

  Main Role
• 
  Kim Hae Sook

  Beom Ho Ja

  Main Role

Support Role

• 
  Kim Min Seok

  Yoo Gi Ho [Hae Jo's helper]

  Support Role
• 
  Lee El

  Bong Suk / Ju Ri [Hae Jo's childhood friend]

  Support Role
• 
  Oh Dae Hwan

  Wang Chil Seong [Leader of pure-hearted faction]

  Support Role
• 
  Kim Soo Jin

  Park Gal Ja

  Support Role
• 
  Lee Hae Young

  Chae Yeong Jo

  Support Role
• 
  Jo Han Chul

  Ko Jae Geun

  Support Role
• 
  Alex Landi

  John Na

  Support Role

Guest Role

• 
  Lee Da Hee

  No Yang Hui (Ep. 1)

  Guest Role
• 
  Kim Seon Hwa

  Jeon Mun Eui (Ep. 1)

  Guest Role
• 
  Kim Chan Hyung

  [Gangster] (Ep. 1)

  Guest Role
• 
  Woo Jung Kook

  [Gangster] (Ep. 1)

  Guest Role
• 
  Lee So Geum

  [Gangster] (Ep. 1)

  Guest Role
• 
  Kim Dae Geun

  [Gangster] (Ep. 1)

  Guest Role
• 
  Park Young Bok

  [Pro Laundry owner] (Ep. 1)

  Guest Role
• 
  Nam Mi Jung

  [Clinic lobby mother] (Ep. 1)

  Guest Role
• 
  Kang Hak Soo

  [Doctor] (Ep. 2)

  Guest Role
• 
  Kim Hee Su

  [Doctor] (Ep. 2)

  Guest Role
• 
  Yoon Boo Jin

  [Shop owner] (Ep. 2)

  Guest Role
• 
  Kim Bong Su

  [Bicycle grandfather] (Ep. 2)

  Guest Role
• 
  Park Jin Young

  [Clinic lobby woman] (Ep. 2)

  Guest Role
• 
  Park Ji Yun

  Eun Su (Ep. 2-3)

  Guest Role
• 
  Ahn Suk Hwan

  O Man Su [Hae Jo's biological father candidate #1] (Ep. 2-3)

  Guest Role
• 
  Jeon Kwang Jin

  [Man Su's son] (Ep. 2-3)

  Guest Role
• 
  Chun Myung Woo

  [Man Su's son] (Ep. 2-3)

  Guest Role
• 
  Jo Yoo Jung

  [Man Su's wife] (Ep. 2-3)

  Guest Role
• 
  Won Chun Gyu

  [Businessman] (Ep. 3)

  Guest Role
• 
  Lee Kwang Ik

  [Customs officer] (Ep. 3)

  Guest Role
• 
  Kim Hyun Kyu

  Kim Min Su (Ep. 3-4)

  Guest Role
• 
  Song Jae Ryong

  Park Seong Sin (Ep. 3-4)

  Guest Role
• 
  Jeon Chi Hwa

  [Police officer] (Ep. 3-4)

  Guest Role
• 
  Jin Yong Wook

  [Perfect Gene's employee] (Ep. 3-4)

  Guest Role
• 
  Jung Ma Rin

  [Train passenger] (Ep. 4)

  Guest Role
• 
  Park Su A

  Cho Jae Mi [Child] (Ep. 5)

  Guest Role
• 
  Kwak Soo Jung

  [Fish seller] (Ep. 5)

  Guest Role
• 
  Yoon Jong Won

  [Fish seller] (Ep. 5)

  Guest Role
• 
  Nam Hee Soo

  [Adoptive mother] (Ep. 5)

  Guest Role
• 
  Oh Soo Hye

  [Blind date] (Ep. 6)

  Guest Role
• 
  Bae Yu Ra

  [Blind date] (Ep. 6)

  Guest Role
• 
  Park Ha Jun

  Hae Jo [Teen] (Ep. 7)

  Guest Role
• 
  Mok Ji Su

  Mi Seon [Ju Ri's employee] (Ep. 7)

  Guest Role
• 
  Choi Da Yeong

  [Nurse] (Ep. 7)

  Guest Role
• 
  Shin Min Soo

  [Taxi driver] (Ep. 7)

  Guest Role
• 
  Choi Ja Woon

  [Bathroom boy] (Ep. 7)

  Guest Role
• 
  Hwang Jung Yoon

  [Debtor] (Ep. 8)

  Guest Role
• 
  Byun Jung Hee

  [Market vendor] (Ep. 8)

  Guest Role
• 
  Kaare Svejgaard Olsen

  [Tiblo executive] (Ep. 8)

  Guest Role
• 
  Kim Jung Ho

  Sin Myeong Su (Ep. 8-9)

  Guest Role
• 
  Ahn Chan Woong

  [Myeong Su's secretary] (Ep. 8-9)

  Guest Role
• 
  Jung Sae Byul

  [Aunt] (Ep. 9)

  Guest Role
• 
  Uhm Hye Soo

  [Nurse] (Ep. 9)

  Guest Role
• 
  Koo Do Kyun

  [Taxi driver] (Ep. 9)

  Guest Role
• 
  Lee Jae Woo

  [Aunt's boyfriend] (Ep. 9)

  Guest Role
• 
  Shim Hye Rim

  [Cellphone store clerk] (Ep. 9)

  Guest Role
• 
  Kim Do Hyeong

  [Hongcheon man] (Ep. 9-10)

  Guest Role
• 
  Lee Sang Hee

  [Hongcheon woman] (Ep. 9-10)

  Guest Role
• 
  Park Gwang Jae

  [Enforcer] (Ep. 10)

  Guest Role
• 
  Kim Kyung Il

  Gong Su

  Guest Role
• 
  Kim Shi Woo

  Chae Seung A

  Guest Role
• 
  Seong No Jin

  Kim Dae Bong

  Guest Role
• 
  Jung Seung Kil

  Choi Jeong Gyu

  Guest Role
• 
  Kim Shi Woo

  Chae Seung Hyeok [Child]

  Guest Role
• 
  Song Yoo Hyun

  Hae Won [Hae Jo's mother]

  Guest Role
• 
  Kim Mi Suk

  [Body]

  Guest Role
• 
  Kim Ji Ahn

  [Woman #1]

  Guest Role
• 
  Seo Ye Bin

  [Stage woman #1]

  Guest Role
• 
  Joo Eun Tae

  [Bonggari member]

  Guest Role
• 
  Yoon Hee Chul

  [Eo Heung's relative]

  Guest Role
• 
  Jung Sun Chul

  [Eo Heung's relative]

  Guest Role
• 
  Moon Chang Wan

  [Heung Kitchen's staff]

  Guest Role
• 
  Park No Kyeong

  [Chil Seong's subordinate]

  Guest Role
• 
  Oh Yong Seok

  [Gangster] (Ep. 1)

  Guest Role

Cameo

• 
  Im Chul Soo

  Ko Yang Hui [Cat group gangster] (Ep. 1)

  Cameo
• 
  Jung Myung Hoon

  Jung Myeong Hun [Video message] (Ep. 1)

  Cameo

Unknown

• 
  Yoo Da Hye Unknown