20th Century Boy and Girl

Assistant Director

• 
  Lee Soo Hyun

Composer

• 
  Jung Se Rin

Director

• 
  Lee Dong Yoon

Music Editor

• 
  Jeon Sang Keun

Screenwriter

• 
  Lee Seon Hye

Main Role

• 
  Han Ye Seul

  Sa Jin Jin

  Main Role
• 
  Kim Ji Suk

  Kong Ji Won

  Main Role
• 
  Lee Sang Woo

  Anthony / Lee Chul Min

  Main Role
• 
  Ryu Hyun Kyung

  Han Ah Reum

  Main Role
• 
  Lee Sang Hee

  Jang Young Shim

  Main Role
• 
  Ahn Se Ha

  Jung Woo Sung

  Main Role
• 
  Oh Sang Jin

  Kang Kyung Suk

  Main Role

Support Role

• 
  Kim Chang Wan

  Sa Chang Wan [Jin Jin's father]

  Support Role
• 
  Kim Mi Kyung

  Kim Mi Gyeong [Jin Jin's mother]

  Support Role
• 
  Shin Won Ho

  Sa Min Ho [Jin Jin's brother]

  Support Role
• 
  Kim Young Sun

  Lee Gwang Hui [Ji Won's mother]

  Support Role
• 
  Shin Se Hwi

  Lee Ha Ram [Ji Won's younger half-sister]

  Support Role
• 
  Kim Tae Hoon

  Lee Seung Goo [Anthony's father / Ji Won's step-father]

  Support Role
• 
  Choi Bum Ho

  Han Hak Gyu [A Reum's father]

  Support Role
• 
  Yoon Bok In

  Yoon Bok In [Ah Reum's mother]

  Support Role
• 
  Park Myung Shin

  Kim Young Ja [Young Shim's mother]

  Support Role
• 
  Kim Ik Tae

  Jang Jang Soo [Young Shim's father]

  Support Role
• 
  Kim Kwang Shik

  Jang Gi Bong [Jin Jin's manager]

  Support Role
• 
  Lee Jae Kyoon

  Lee Hong Hee [Jin Jin's road manager]

  Support Role
• 
  Lee You Mi

  Mi Dal / Cho Min Hyeon [Jin Jin's stylist]

  Support Role
• 
  Shin Dong Mi

  Choi Jung Eun [Anthony's manager]

  Support Role
• 
  Jang Jae Ho

  Kim Tae Hyun [Ji Won's assistant]

  Support Role
• 
  Jang Hee Ryung

  Jang Ji Hye [Flight attendant]

  Support Role
• 
  Cha Seo Won

  Lee Dong Hoon [Co-pilot]

  Support Role
• 
  Kang Mi Na

  Sa Jin Jin [Young]

  Support Role
• 
  Kim In Seong

  Gong Ji Won [Young]

  Support Role
• 
  Park Seo Ham

  Anthony [Young]

  Support Role
• 
  Song Soo Hyun

  Han Ah Reum [Young]

  Support Role
• 
  Lee Chang

  PD Bong

  Support Role
• 
  Han Ji Won

  Jang Young Shim [Young]

  Support Role
• 
  Au Hin Wai Support Role

Guest Role

• 
  Kim Ha Yun

  Sa Jin Jin [Child]

  Guest Role
• 
  Jo Yeon Ho

  Gong Ji Won [Child]

  Guest Role
• 
  Lee Han Seo

  Ah Reum [Child]

  Guest Role
• 
  Do Yeong Seo

  Young Shim [Child]

  Guest Role
• 
  Kwon Do Kyun

  Jung Woo Sung [Young]

  Guest Role
• 
  Kim Jung Hwa

  Sa Ho Sung / Lee Soo Hyun [Jin Jin's older sister]

  Guest Role
• 
  Lee Dae Yeol

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Kim Dong Hyun

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Y

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Park Jae Seok

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Universe

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Lee Jang Jun

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Bae Seung Min

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Bong Jae Hyun

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Hong Joo Chan

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Choi Bo Min

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Kim Ji Beom

  [Himself] (Ep. 1, 3)

  Guest Role
• 
  Heo Ji Woong

  [Himself] (Ep. 2)

  Guest Role
• 
  Lee Joon Gi

  [Jin Jin's father] [Voice] (Ep. 4)

  Guest Role
• 
  Lee Yoon Sang

  [Rejected client] (Ep. 4)

  Guest Role
• 
  Park Yong

  [Rejected client] (Ep. 4)

  Guest Role
• 
  Park Seung Tae

  [Elder couple in elevator] (Ep. 6, 9)

  Guest Role
• 
  Han Tae Il

  [Elder couple in elevator] (Ep. 6)

  Guest Role
• 
  Yeo Woon Bok

  [Ji Won's father](Ep. 7-8)

  Guest Role
• 
  Park Seul Ki

  ["We Got Married" MC] (Ep. 11)

  Guest Role
• 
  Park Eun Ji

  ["We Got Married" MC] (Ep. 13)

  Guest Role
• 
  Ji Yoon Ho

  Hyun Woo ["We Got Married" cast member] (Ep. 14)

  Guest Role
• 
  Lee Chae Kyung

  [Director Shin's team] (Ep. 19)

  Guest Role
• 
  Jo Sun Mook

  [National Chemicals] (Ep. 19)

  Guest Role
• 
  Lee Nam Hee

  [Taxi driver] (Ep. 20)

  Guest Role
• 
  Baek Yoon Heum

  [Reporter] (Ep. 22)

  Guest Role
• 
  Shin Dong Hoon

  Jung Yung Jin [Reporter]

  Guest Role
• 
  Han Sun Hwa

  Jung Da Young [Model / Actress]

  Guest Role
• 
  Kim Shin Young

  [Herself] | [Radio DJ]

  Guest Role
• 
  Jo Hyun Sik

  [School van driver]

  Guest Role
• 
  Shim Hyung Tak

  Terius / Jung Chang Hoon

  Guest Role
• 
  Woo Je Yeon

  [Boys Be Ambitious idol group member]

  Guest Role
• 
  Kim Ji Hun

  [Boys Be Ambitious idol group member]

  Guest Role
• 
  Kim You Jin

  [Boys Be Ambitious idol group member]

  Guest Role
• 
  Jeong In Seong

  [Boys Be Ambitious idol group member]

  Guest Role
• 
  Jung Ji Young

  Jung Ji Young [DJ]

  Guest Role
• 
  Kim So Yeon

  Director Kim

  Guest Role
• 
  Kim Seung Chan

  Jong Hwa

  Guest Role
• 
  Kim Gun

  [Chubby elementary school student]

  Guest Role
• 
  Kim Su In

  [Elementary school student]

  Guest Role
• 
  Woo Sung Min

  [Boy fan of Jin Jin]

  Guest Role
• 
  Kim Seo Jung

  Hee Jin [Woo Sung's date]

  Guest Role
• 
  Ok Joo Ri

  [Lawyers cleaning lady]

  Guest Role
• 
  Hong Boo Hyang

  [Mother of child]

  Guest Role
• 
  Hong Ye Ji

  [Nurse]

  Guest Role
• 
  Joo Byung Ha

  [Flight attendant's husband]

  Guest Role
• 
  Ham Jin Sung

  [CF assistant director]

  Guest Role
• 
  Kim Mi Hye

  [News Anchor]

  Guest Role
• 
  Kim Jin Goo

  [Mediator]

  Guest Role
• 
  Kim Baek Ri

  [Crew member]

  Guest Role
• 
  Choo Soo Bin Guest Role
• 
  Yook Mi Ra Guest Role
• 
  Kwon Hyuk Soo Guest Role
• 
  Jang Tae Min Guest Role
• 
  Shin Bo Ra Guest Role
• 
  Jung Mi Mi Guest Role
• 
  Kim Na Young Guest Role
• 
  Ha Jin Guest Role
• 
  Jung Jong Woo Guest Role
• 
  Kim Na Moo Guest Role

Unknown

• 
  Kim Hyo Myung Unknown
• 
  Bae Min Jun Unknown
• 
  Park Tae Yun Unknown