Adult Trainee

Composer

• 
  Choi In Hee

Director

• 
  Yoo Hak Chan

Main Role

• 
  Ryu Eui Hyun

  Seo Jae Min (Ep. 1-2)

  Main Role
• 
  Cho Mi Yeon

  Park Ye Gyeong (Ep. 1-2)

  Main Role
• 
  Jo Yoo Jung

  Ban Yu Ra (Ep. 3-5)

  Main Role
• 
  Ryeo Un

  Kim Nam Ho (Ep. 3-5)

  Main Role
• 
  Kwon Yeong Eun

  Son Na Eun (Ep. 6-7)

  Main Role
• 
  Kim Min Ki

  Choi Gang Jun (Ep. 6-7)

  Main Role

Support Role

• 
  Lee Chan Hyeong

  Song I Jun (Ep. 3-5)

  Support Role
• 
  Park Se Hyun

  Kang Da Hyeon (Ep. 3-5)

  Support Role
• 
  Kang Yi Suk

  Kim Seong Jae (Ep. 6-7)

  Support Role
• 
  Song Chae Yun

  Kang Go Eun (Ep. 6-7)

  Support Role
• 
  Lee Kang Ji

  Ha Jae Mu

  Support Role
• 
  Oh Ki Chan

  Lee Min Ho

  Support Role
• 
  Jang Sung Yoon

  Song Hye Bin

  Support Role
• 
  Jo Sung Joon

  Jin Beom

  Support Role

Guest Role

• 
  Son Joo Yeon

  [Jae Min's mother] (Ep. 1)

  Guest Role
• 
  Choi Kwang Je

  [Vlogger] (Ep. 1)

  Guest Role
• 
  Lee Sang Eun

  [Art teacher] (Ep. 1)

  Guest Role
• 
  Jung Sung Young

  [Caught student] (Ep. 1-2)

  Guest Role
• 
  Kim Han Jong

  Myeong Han [Teacher] (Ep. 2)

  Guest Role
• 
  Park Jin Soo

  [Couple wanting park bench] (Ep. 2)

  Guest Role
• 
  Choi Gyo Shik

  [School security guard] (Ep. 2)

  Guest Role
• 
  Choi Yeon Soo

  Se Yeong (Ep. 3-5)

  Guest Role
• 
  Yoo Ji Yeon

  [Student] (Ep. 3-5)

  Guest Role
• 
  Seo Young Sam

  [Geology teacher] (Ep. 3, 6)

  Guest Role
• 
  Lee Si Young

  [School nurse] (Ep. 4)

  Guest Role
• 
  Lee So Geum

  [Convenience store cashier] (Ep. 4)

  Guest Role
• 
  Kim Sung Yong

  [Teacher] (Ep. 4)

  Guest Role
• 
  Lee Hye Eun

  [Yu Ra's mother] (Ep. 5)

  Guest Role
• 
  Jung Yeon Shim

  [Nam Ho's mother] (Ep. 5)

  Guest Role
• 
  Park Min Young

  [PE teacher] (Ep. 5)

  Guest Role
• 
  Kwak Ji Yoo

  [PE teacher] (Ep. 6)

  Guest Role
• 
  Oh Se Eun

  Yoo Ja Sun

  Guest Role
• 
  Kang Cho Won

  Kim Da Song

  Guest Role
• 
  Choi Jang Cheon

  Choi Seong Uk

  Guest Role
• 
  Ahn Jin Hyun

  Park Mi Gyeong

  Guest Role
• 
  Jung Je Hyun

  Park Jun Ha

  Guest Role
• 
  Lee Seon Hee

  [Na Eun's mother]

  Guest Role
• 
  Lee Hwi Won

  [Self-disciplined student]

  Guest Role
• 
  Lee Ji Young

  [Math teacher]

  Guest Role
• 
  Lee Na Hyun

  [Music teacher]

  Guest Role