Twinkling Watermelon

Chief Producer

• 
  Lee Ki Hyuk

Director

• 
  Son Jung Hyun

Producer

• 
  Park Sang Hyun

Screenwriter

• 
  Jin Soo Wan

Main Role

• 
  Ryeo Un

  Ha Eun Gyeol

  Main Role
• 
  Choi Hyun Wook

  Ha I Chan

  Main Role
• 
  Seol In Ah

  Choi Se Gyeong | On Eun Yu

  Main Role
• 
  Shin Eun Soo

  Yun Cheong A

  Main Role

Support Role

• 
  Kim Joo Ryoung

  Lim Ji Mi [Cheong A's stepmother]

  Support Role
• 
  Bong Jae Hyun

  Ha Eun Ho [Eun Gyeol’s brother]

  Support Role
• 
  Choi Won Young

  Ha I Chan [Older]

  Support Role
• 
  Seo Young Hee

  Yun Cheong A [Older]

  Support Role
• 
  Cheon Ho Jin

  Viva [Eun Gyeol's mentor]

  Support Role
• 
  Jung Sang Hoon

  [Master]

  Support Role
• 
  Lee Suk Hyeong

  Jung Bal San [College student]

  Support Role
• 
  Ahn Do Kyu

  O Ma Ju [Band manager]

  Support Role
• 
  Yoon Jae Chan

  Kang Hyeon Yul [Bassist]

  Support Role
• 
  Lee Su Chan

  No Se Beom [Keyboardist]

  Support Role
• 
  Lee Ha Min

  Lee Si Guk [Drummer]

  Support Role
• 
  Woo Je Yeon

  On Ji Hwan

  Support Role
• 
  Koo Jun Hoe

  Koo Jun Hyeong [Spine9's vocalist]

  Support Role
• 
  Han Min

  Bae Su Tak [Spine9’s bassist]

  Support Role
• 
  Yeon Oh

  Jung Ji O [Spine9’s drummer]

  Support Role
• 
  Lee So Yeon

  Choi Se Gyeong [Older]

  Support Role
• 
  Go Doo Shim

  Ko Yang Hui [I Chan’s grandmother]

  Support Role
• 
  Lee Soo Min

  Yun Sang A [Se Gyeong’s friend]

  Support Role
• 
  Kim Tae Woo

  Yun Gun Hyeong [Cheong A's father]

  Support Role
• 
  Kwon Do Hyung

  Yun Ju Yeop [Cheong A's stepbrother]

  Support Role
• 
  Kim Ye Ji

  Lee Mi Ra

  Support Role
• 
  Kim Hyung Beom

  O Ma Ju [Older]

  Support Role
• 
  Shin Hyun Yong

  [PE teacher]

  Support Role

Guest Role

• 
  Kim Ji Woo

  Ha Eun Ho [Young] (Ep. 1)

  Guest Role
• 
  Jung Hyun Joon

  Ha Eun Gyeol [Young] (Ep. 1)

  Guest Role
• 
  Noh Hee Joong

  [Worker] (Ep. 1)

  Guest Role
• 
  Kim Moon Ho

  [Vegetables supplier] (Ep. 1)

  Guest Role
• 
  Jeong Yu Jin

  [Cafe staff] (Ep. 1)

  Guest Role
• 
  Heo Jung Min

  [Coffee shop manager] (Ep. 1)

  Guest Role
• 
  Kim Ha Eon

  Yeom Byeong Ho (Ep. 1-2)

  Guest Role
• 
  Kim Mi Hwa

  [Byeong Ho’s mother] (Ep. 1-2)

  Guest Role
• 
  Kyung Ki Hyun

  [Talent agent] (Ep. 2)

  Guest Role
• 
  Lee Won Jin

  [Police officer] (Ep. 2)

  Guest Role
• 
  Lee Bong Ha

  [Eun Gyeol's helper] (Ep. 2)

  Guest Role
• 
  O Gyu Taek

  [Se Gyeong's chauffeur] (Ep. 2-3)

  Guest Role
• 
  Shin Young Kyu

  Yong Jun Gi (Ep. 3)

  Guest Role
• 
  Kim Dong Gyun

  [Math teacher] (Ep. 3)

  Guest Role
• 
  Lee Seung Chul

  [Unhoused man] (Ep. 3)

  Guest Role
• 
  Jeon Seok Chan

  [The Day owner] (Ep. 3, 5)

  Guest Role
• 
  Moon Seo Yeon

  Choi Se Gyeong [Young] (Ep. 4)

  Guest Role
• 
  Oh Hyun Kyung

  Sin Ha Yeong [Se Gyeong's mother] (Ep. 4-5)

  Guest Role
• 
  Cho Yeo Jun

  Ha Eun Ho [Child] (Ep. 4)

  Guest Role
• 
  Cha Young Mi

  [Maid] (Ep. 4)

  Guest Role
• 
  Han Ji Eun

  [Cello instructor] (Ep. 4)

  Guest Role
• 
  Yoon Hyo Sik

  [Se Gyeong's dad] (Ep. 4)

  Guest Role
• 
  Park Ho San

  Choi Hyeon [Baekya Music's owner] (Ep. 5-6, 10-12, 14-16)

  Guest Role
• 
  Kwon Dan Ah

  Yun Cheong A [Young] (Ep. 6)

  Guest Role
• 
  Kim Eui Shin

  [Store owner] (Ep. 6)

  Guest Role
• 
  Lee Seol Hee

  [Yun Cheong A's mother] (Ep. 6)

  Guest Role
• 
  Kim Hae Jun

  DJ Jun (Ep. 7)

  Guest Role
• 
  Ryu Jin

  On Ji Hwan [Adult] (Ep. 7)

  Guest Role
• 
  Woo Jeong Won

  Yun Sang A [Adult] (Ep. 7)

  Guest Role
• 
  Lee Sang Hoon

  Attorney Jang (Ep. 8)

  Guest Role
• 
  Kim So Eun

  Jung Hyun Jung [Nurse] (Ep. 8)

  Guest Role
• 
  Kim Bong Hui

  [Hospital patient] (Ep. 8)

  Guest Role
• 
  Kim Jun Seok

  [Students' dean] (Ep. 9)

  Guest Role
• 
  Eom Ji Man

  [Students' dean] (Ep. 9)

  Guest Role
• 
  Yoon Do Hyun

  Yun Dong Jin [Older] (Ep. 10)

  Guest Role
• 
  Kim Jun Hyung

  Yun Dong Jin [Young] (Ep. 10)

  Guest Role
• 
  Yoo Yi Ha

  [Cellist student] (Ep. 10)

  Guest Role
• 
  Lee Moo Nyoung

  [Restaurant worker] (Ep. 10)

  Guest Role
• 
  Lee Eun Mi

  [Liquor store owner] (Ep. 10)

  Guest Role
• 
  Park Han Sol

  [Eun Ho's girlfriend] (Ep. 10)

  Guest Role
• 
  Hong Suk Youn

  Jung Su Bin (Ep. 11)

  Guest Role
• 
  Park Woo Young

  Lee Gang Hun (Ep. 11)

  Guest Role
• 
  Jung Yong Ju

  Jung Do Jin (Ep. 11, 15)

  Guest Role
• 
  Do Geon Wu

  [Gang member] (Ep. 11)

  Guest Role
• 
  Lee Dong Gi

  [Gang member] (Ep. 11)

  Guest Role
• 
  Jin Hui Gyu

  [Incarcerated juvenile] (Ep. 11)

  Guest Role
• 
  Lee So Hee

  Ji Min (Ep. 13)

  Guest Role
• 
  Jung Kyu Soo

  Kang Jung Man [Principal] (Ep. 13)

  Guest Role
• 
  Jeon Jeong Il

  [Taxi driver] (Ep. 13)

  Guest Role
• 
  Kang Yi Suk

  [Dongwon High student] (Ep. 13)

  Guest Role
• 
  Byun Gun Woo

  [Convenience store cashier] (Ep. 13)

  Guest Role
• 
  Moon Hyeon Jeong

  [Maid] (Ep. 14)

  Guest Role
• 
  Kim So Min

  [Sidewalk boy] (Ep. 15)

  Guest Role
• 
  Ryu Soo Young

  Lee Si Guk [Older] (Ep. 16)

  Guest Role
• 
  Jin Tae Hyun

  No Se Bum [Older] (Ep. 16)

  Guest Role
• 
  Song Chang Eui

  Kang Hyun Yul [Older] (Ep. 16)

  Guest Role
• 
  Baek Seung Hyun

  [Detective] (Ep. 16)

  Guest Role
• 
  Yoo Su A

  Ji Hye Su

  Guest Role
• 
  Kim Ji Yeon

  Da Yeon

  Guest Role
• 
  Choi Yoon Woo

  Yun Ju Yeop [Young]

  Guest Role
• 
  Park Jung Hoon

  Lee Jong Gwan [Astronomical department]

  Guest Role
• 
  Shin Young Chan

  [Boarder]

  Guest Role
• 
  Yoon Dong Hwan

  [Boarder]

  Guest Role
• 
  Yoon Jung Hoon

  [Music teacher]

  Guest Role
• 
  Lee Sae Byul

  [PR team leader]

  Guest Role
• 
  Jung Kang Hee

  [Club Spark boss]

  Guest Role
• 
  Park Sun Woo Guest Role
• 
  Kim Hee Sung Guest Role

Unknown

• 
  Yoo Da Hye Unknown

Bit part

• 
  Byeon Chang Yeol

  [Middle-aged man]

  Bit part