Happiness

Composer

• 
  Kim Tae Seong

Director

• 
  Ahn Gil Ho

Editor

• 
  Steve M. Choe

Screenwriter

• 
  Han Sang Woon

Main Role

• 
  Han Hyo Joo

  Yun Sae Bom

  Main Role
• 
  Park Hyung Sik

  Jung I Hyeon

  Main Role
• 
  Jo Woo Jin

  Han Tae Seok

  Main Role

Support Role

• 
  Lee Joon Hyuk

  Kim Jeong Guk

  Support Role
• 
  Park Joo Hee

  Lee Ji Su

  Support Role
• 
  Baek Hyun Jin

  O Ju Hyeong

  Support Role
• 
  Moon Ye Won

  Woo Sang Hui

  Support Role
• 
  Park Hyung Soo

  Kook Hae Seong

  Support Role
• 
  Jeong Un Seon

  Sin So Yun

  Support Role
• 
  Song Ji Woo

  Park Seo Yun

  Support Role
• 
  Bae Hae Seon

  O Yeon Ok

  Support Role
• 
  Cha Soon Bae

  Seon U Chang

  Support Role
• 
  Han Joon Woo

  Kim Se Hun

  Support Role
• 
  Park Hee Von

  Na Hyeon Gyeong

  Support Role
• 
  Na Chul

  Na Su Min

  Support Role
• 
  Lee Joo Shil

  Ji Seong Sil

  Support Role
• 
  Hong Soon Chang

  Kim Hak Je

  Support Role
• 
  Kang Han Saem

  Kim Dong Hyeon

  Support Role
• 
  Kim Young Woong

  Ko Se Gyu

  Support Role
• 
  Lee Ji Ha

  Ji Mun Hui

  Support Role
• 
  Lee Ju Seung

  Andrew / Choi Jong Wook

  Support Role
• 
  Han Da Sol

  Lee Bo Ram

  Support Role
• 
  Nam Mi Jung

  Lee Deok Sun

  Support Role
• 
  Joo Jong Hyuk

  Kim Seung Beom [Seyang personal trainer]

  Support Role

Guest Role

• 
  Nam Sang Woo

  Lee Jong Tae (Ep. 1)

  Guest Role
• 
  Kim Yeon Woo

  Il Ho (Ep. 1)

  Guest Role
• 
  Han Sa Myung

  Seong U Je (Ep. 1)

  Guest Role
• 
  Park Sung Il

  [Seyang High teacher] (Ep. 1)

  Guest Role
• 
  Choi Yi Sun

  [Motel clerk] (Ep. 1)

  Guest Role
• 
  Seon Yul U

  [Detective, Seyang Police Station] (Ep. 1)

  Guest Role
• 
  Yoo Tae Joo

  [Guard post soldier] (Ep. 1)

  Guest Role
• 
  Lee Kyu Hyung

  Lee Seung Yeong [Special ops unit] (Ep. 1-3, 8, 12)

  Guest Role
• 
  Baek Sung Chul

  [Reporter] (Ep. 2)

  Guest Role
• 
  Baek Joo Hee

  Park Min Ji [Ju Hyeong's wife] (Ep. 2-3)

  Guest Role
• 
  Kang Ji Eun

  Kim Bok Nam [Sae Bom's mother] (Ep. 2-3)

  Guest Role
• 
  Yoon Sang Won

  Kang Ju Heon [Trainer] (Ep. 2-3)

  Guest Role
• 
  Jung Jae Eun

  [I Hyeon's mother] (Ep. 3)

  Guest Role
• 
  Seo Hyun Chul

  [I Hyeon's father] (Ep. 3)

  Guest Role
• 
  Jeon Seok Chan

  Park Yong Cheol [Seo Yoon's father, #502] (Ep. 3)

  Guest Role
• 
  Kim Shi Heon

  [Paramedic] (Ep. 3)

  Guest Role
• 
  Park Chul Min

  [Anchorman] (Ep. 3)

  Guest Role
• 
  Lee Gi Young

  Choi Seok Ju [Atum Therapeutics Chairman] (Ep. 3-4, 7-9)

  Guest Role
• 
  Kim Joo Yeon

  Kang Eun Ji

  Guest Role
• 
  Lee Dong Gyu

  [TNBC anchorman] (Ep. 4)

  Guest Role
• 
  Jung Min Sung

  [Bulding #102 resident] (Ep. 4-7)

  Guest Role
• 
  Park Hee Eun

  [Resident] (Ep. 5)

  Guest Role
• 
  Park Ki Ryung

  [Prime minister] (Ep. 5)

  Guest Role
• 
  Yoo Ji Yeon

  Park Yeong In [Tae Seok's wife] (Ep. 8)

  Guest Role
• 
  Yoon Bok Sung

  [Politician] (Ep. 8)

  Guest Role
• 
  Lee Seung Joon

  Kim Tae Yun [Brigadier general] (Ep. 12)

  Guest Role
• 
  Ahn Ji Hwan

  An Guk Jin

  Guest Role
• 
  Sun Young Uk

  [Seyang Forest Le Ciel security guard]

  Guest Role
• 
  Jung Hyeon Ok

  [Infectee]

  Guest Role