Hello, My Twenties!

Composer

• 
  Lee Nam Yeon

Director

• 
  Lee Tae Gon

Screenwriter

• 
  Park Yeon Sun

Main Role

• 
  Han Ye Ri

  Yun Jin Myeong

  Main Role
• 
  Han Seung Yeon

  Jung Ye Eun

  Main Role
• 
  Park Eun Bin

  Song Ji Won

  Main Role
• 
  Ryu Hwa Young

  Kang I Na

  Main Role
• 
  Park Hye Soo

  Yoo Eun Jae

  Main Role

Support Role

• 
  Yoon Bak

  Park Jae Wan [Chef]

  Support Role
• 
  Choi Duk Moon

  O Jong Gyu [I Na's mystery man]

  Support Role
• 
  Ji Il Joo

  Ko Du Yeong [Ye Eun's boyfriend]

  Support Role
• 
  Shin Hyun Soo

  Yun Jong Yeol [Eun Jae's senior]

  Support Role
• 
  Son Seung Won

  Im Seong Min [Ji Won's friend]

  Support Role
• 
  Yoon Jong Hoon

  Seo Dong Ju [I Na's friend]

  Support Role
• 
  Moon Sook

  [Belle Epoque landlady]

  Support Role
• 
  Lee Gyeong Shim

  An Jeong Hui [Eun Jae's mother]

  Support Role
• 
  Kim Yong Hee

  [I Na's dentist]

  Support Role
• 
  Min Sung Wook

  [Restaurant manager / Jin Myeong's boss]

  Support Role
• 
  Park Se Mi

  Cho Hyeon Hui [Restaurant waitress]

  Support Role
• 
  Han Jung Woo

  [I Na's secondary boyfriend]

  Support Role
• 
  Song Ji Ho

  [I Na's stalker]

  Support Role
• 
  Ha Eun Seol

  Han Yu Gyeong [Ye Eun's friend]

  Support Role
• 
  Choi Bae Young

  Song Gyeong A [Ye Eun's friend]

  Support Role
• 
  Yoon Yong Joon

  Sin Yul Bin [Jong Yeol's friend] (Ep. 4-5, 12)

  Support Role
• 
  Kim Kyung Nam

  [Psychology major]

  Support Role
• 
  Kim Chang Hwan

  [Insurance company employee]

  Support Role
• 
  Nam Moon Chul

  [Ji Won's father]

  Support Role
• 
  Kwon Eun Soo

  Kim Han So Yeong [Jong Yeol's junior]

  Support Role
• 
  Shin Yeon Suk

  [Eun Jae's aunt]

  Support Role
• 
  Lee Na Yoon

  Yoo Eun Jae [Young]

  Support Role
• 
  Tak Woo Suk Support Role
• 
  Park Soo Oh

  [11yo Eun Jae's older brother]

  Support Role

Guest Role

• 
  Lee Jung Hyun

  [Backpack bus passenger] (Ep. 1)

  Guest Role
• 
  Song Yu Vin

  [Ji Won's date] (Ep. 3)

  Guest Role
• 
  Park Sang Nam

  [Coffee shop waiter / Barista] (Ep. 3)

  Guest Role
• 
  Park Kyung Hye

  [New candidate for a roommate] (Ep. 4)

  Guest Role
• 
  Joey Albright

  Samuel Johnson [Invited party guest] (Ep. 5)

  Guest Role
• 
  Ham Na Young

  Jae Yeon [Stumbled girl] (Ep. 8)

  Guest Role
• 
  Kim Si Eun

  Jin Myeong

  Guest Role
• 
  Kim Dan Woo

  Yoo Eun Jae [Child]

  Guest Role
• 
  Hong Seung Beom

  [Physician]

  Guest Role
• 
  Jo Seung Yeon

  [Kid's mom]

  Guest Role
• 
  Dong Hyun Bae

  [Kitchen porter]

  Guest Role
• 
  Cha Bo Sung

  [Blind date man]

  Guest Role
• 
  Jung Yoo Min

  [Dancing student]

  Guest Role
• 
  Lee Seon Joo

  [Boyfriend's mother]

  Guest Role
• 
  Yoo Joo Won

  [Son in bicycle scene]

  Guest Role
• 
  Han Tae Il

  [Yi Na's house of call guest]

  Guest Role
• 
  Jo Mi Nyeo

  [Student who has got Eun Jae's ballpoint]

  Guest Role
• 
  Lee Chae Kyung

  [Professor in the Department of Food and Nutrition]

  Guest Role
• 
  Ham Jin Sung

  [Station attendant]

  Guest Role
• 
  Kim I So

  [College student]

  Guest Role
• 
  Han Seong Hyeon

  [Student]

  Guest Role
• 
  Jang Tae Min Guest Role
• 
  Lee Jae Eun Guest Role
• 
  Kang So Eun Guest Role
• 
  Lee Jin Mok Guest Role
• 
  Hong Hee Won Guest Role
• 
  Jung Myung Joon Guest Role
• 
  Choi Gyo Shik Guest Role
• 
  Moon Ki Young Guest Role
• 
  Kim Sun Bin Guest Role
• 
  Kwon Young Kyung Guest Role
• 
  Seol Chang Hee Guest Role
• 
  Ahn Soo Bin Guest Role
• 
  Seon Ah Rin Guest Role
• 
  Kwon Oh Kyung Guest Role
• 
  Geum Joon Hyun Guest Role

Unknown

• 
  Kim Joo Young Unknown