On the Verge of Insanity

Composer

• 
  Park Se Jun

Director

• 
  Choi Jung In

Screenwriter

• 
  Jung Do Yoon

Main Role

• 
  Jung Jae Young

  Choi Ban Seok

  Main Role
• 
  Moon So Ri

  Dang Ja Yeong

  Main Role
• 
  Lee Sang Yeob

  Han Se Kwon

  Main Role
• 
  Kim Ga Eun

  Seo Na Ri

  Main Role

Support Role

• 
  Kim Nam Hee

  Shin Han Soo

  Support Role
• 
  Ahn Nae Sang

  Noh Byung Guk

  Support Role
• 
  Park Won Sang

  Paeng Soo Gon

  Support Role
• 
  Park Sung Geun

  Gong Jung Pil

  Support Role
• 
  Kim Joong Ki

  Ko Jeong Shik

  Support Role
• 
  Jo Bok Rae

  Han Seung Gi [Chairman]

  Support Role
• 
  Cha Chung Hwa

  Shin Jung Ah

  Support Role
• 
  Dong Hyun Bae

  Ki Jeong Hyun

  Support Role
• 
  Lee Seo Joon

  Ahn Jun Soo

  Support Role
• 
  Cheon Hee Joo

  Gye Bo Ram

  Support Role
• 
  Lim Il Gyu

  Oh Jae Il

  Support Role
• 
  Jung Sung Hoon

  Yoon Gi Joon

  Support Role
• 
  Kim Yae Eun

  Oh Hye Yeon

  Support Role
• 
  Lim Hyoun Soo

  So Sang Wook

  Support Role
• 
  Choi Myung Gil

  Choi Hye Soo [Na Ri's mother]

  Support Role
• 
  Baek Min Hyun

  Ahn Joon Soon [Member of robot cleaner development team]

  Support Role
• 
  Jung Yeo Joon

  Gil Chang Hwan [Member of QA Team]

  Support Role
• 
  Oh Yong

  Pyeon Dong Il

  Support Role
• 
  Kim Jin Ho

  Bae Jung Tak

  Support Role
• 
  Jung Ye Na

  Choi Seon Yi [Ban Seok's daughter]

  Support Role
• 
  Nam Neung Mi

  [Ban Seok's mother]

  Support Role
• 
  Yang Jae Hyun

  Yoo Woo Jong

  Support Role
• 
  Son Ye Ji

  Park Da Som [Purchasing department senior]

  Support Role
• 
  Choi Yoon Jung

  Dang Min Young [Ja Young's sister]

  Support Role
• 
  Koo Min Hyuk

  Jeon Myung Woo [Development team 3 manager]

  Support Role
• 
  Kim Yun Seo

  Jeong Seong Eun

  Support Role
• 
  Kim Gyu Do

  Cha Gyu Won [Development team #3 senior]

  Support Role
• 
  Oh Yoo Na

  Heo Ga Young [Product Planning]

  Support Role
• 
  Jung Hyun Chul

  Sung Do Gyun

  Support Role

Guest Role

• 
  Song Yo Sep

  Jin Seung Ho (Ep. 1)

  Guest Role
• 
  Chu Eun Kyung

  Jo Sun Young (Ep. 1)

  Guest Role
• 
  Choi Duk Moon

  Kim Young Soo (Ep. 1, 15)

  Guest Role
• 
  Jeon Yeo Jin

  Headhunter (Ep. 3)

  Guest Role
• 
  Kim Han Joon

  Mr. Jung [AA Electronics] (Ep. 3)

  Guest Role
• 
  Kim Shin Yul

  [Executive] (Ep. 5)

  Guest Role
• 
  Kim Gyeong Min

  Shin Jong Sik [QK Korea] (Ep. 8)

  Guest Role
• 
  Lee Sung Il

  [Auditor] (Ep. 8-9)

  Guest Role
• 
  Park Ki Ryung

  Park Ki Ryoong (Ep. 8, 16)

  Guest Role
• 
  Kwak Min Seok

  Lee Hyun Joong (Ep. 10)

  Guest Role
• 
  Jang Dae Woong

  [Executive] (Ep. 10)

  Guest Role
• 
  Lee Jun I

  [Gas station attendant] (Ep. 10)

  Guest Role
• 
  Son Seon Geun

  [Hanmyeong HQ executive] (Ep. 10)

  Guest Role
• 
  Jung Dong Gyu

  [Mayor] (Ep. 11)

  Guest Role
• 
  Jang Joon Hyun

  Lee Kyung Hoon (Ep. 12)

  Guest Role
• 
  Kwon Hyuk Soo

  [Han Seung Gi's uncle] (Ep. 14)

  Guest Role
• 
  Jeong Young Do

  [Reporter] (Ep. 14)

  Guest Role
• 
  Kim Sang Il

  Mr. Yoon [Hanmyeong E & C] (Ep. 15)

  Guest Role
• 
  Kim Jae Il

  Kang Jae Hyuk [GR Tech] (Ep. 16)

  Guest Role
• 
  Hwang Tae Kwang

  Son Tae Sung (Ep. 16)

  Guest Role
• 
  Uhm Hye Soo

  Lee Han Sol (Ep. 16)

  Guest Role
• 
  Park Byung Wook

  [Executive] (Ep. 16)

  Guest Role
• 
  Kim Pan Kyum

  [CEO's assistant] (Ep. 16)

  Guest Role
• 
  Park Chang Woo

  Dong Gyoo

  Guest Role
• 
  Yoo Sang Jae

  Son Hyung Ki [Finance team]

  Guest Role
• 
  Park Keun Rok

  Han Seung Jin [Hanmyeong E & C ]

  Guest Role
• 
  Kim Jin Goo

  [Hanmyeong Electronics HQ executive]

  Guest Role
• 
  Yoo Jung Rae

  Eo Hae Mi [Research & Development]

  Guest Role
• 
  Choi Yoon Jung

  Dang Min Yeong

  Guest Role
• 
  Yoon Hae Joo

  [Director Eun's voice]

  Guest Role
• 
  Kang In Gi

  No Jae Yeol

  Guest Role
• 
  Park Jin Soo

  Seo Yoon Taek

  Guest Role