Secret Royal Inspector & Joy

Composer

• 
  Dalpalan

Director

• 
  Yoo Jong Sun

Music Editor

• 
  Lee Min Hwi

Screenwriter

• 
  Lee Jae Yoon

Main Role

• 
  Ok Taec Yeon

  Ra Yi Eon

  Main Role
• 
  Kim Hye Yoon

  Kim Jo Yi

  Main Role

Support Role

• 
  Lee Jae Kyoon

  Park Tae Seo

  Support Role
• 
  Bae Jong Ok

  Deok Bong [Tail Island]

  Support Role
• 
  Jeong Bo Seok

  Park Seung [Chief State councillor]

  Support Role
• 
  Min Jin Woong

  Yook Chil

  Support Role
• 
  Park Kang Sub

  Goo Pal

  Support Role
• 
  Chae Won Bin

  Bi Ryung | Hwang Bo Ri

  Support Role
• 
  Lee Sang Hee

  Ra Kwang Soon

  Support Role
• 
  Choi Tae Hwan

  Park Do Soo

  Support Role
• 
  Jung Soon Won

  Cha Mal Jong

  Support Role
• 
  Kim Hyun Jun

  Ji Maeng Soo

  Support Role
• 
  Park Shin Ah

  Kang Han Ki

  Support Role
• 
  Cha Yeob

  Hong Seok Gi

  Support Role
• 
  Yoo Dong Hun

  Eo Moo Jeok (Ep. 4-5, 16)

  Support Role

Guest Role

• 
  Kim In Kwon

  Chil Bok [Hongmungwan Inspector] (Ep. 1)

  Guest Role
• 
  Go Han Min

  [Royal scholar] (Ep. 1, 10)

  Guest Role
• 
  Kwon Oh Kyung

  [Royal scholar] (Ep. 1, 10))

  Guest Role
• 
  Han Dae Gwan

  [Fisherman] (Ep. 1-2)

  Guest Role
• 
  Sung Hyun Mi

  [Divorce hearing spectator] (Ep. 1-2)

  Guest Role
• 
  Joo Jin Soo

  No Chu Han (Ep. 1-3)

  Guest Role
• 
  Song Jong Ho

  Jang Ki Wan [Left Chungcheong province magistrate] (Ep. 1-3)

  Guest Role
• 
  Choi Hwan Yi

  [Divorce hearing spectator] (Ep. 1-3)

  Guest Role
• 
  Kim Kwang Sub

  [Divorce hearing spectator] (Ep. 1-3)

  Guest Role
• 
  Kim Yun Jeong

  [Divorce hearing spectator] (Ep. 1-3)

  Guest Role
• 
  Park Seung Tae

  [Divorce hearing spectator] (Ep. 1-3)

  Guest Role
• 
  Nam Mi Jung

  Jang Pad Soon (Ep. 1-3, 7)

  Guest Role
• 
  Cho Hee Bong

  Mi Ahn Hae [Left Chungcheong province official] (Ep. 1-3, 5-7)

  Guest Role
• 
  Kim Ki Nam

  [Royal scholar] (Ep. 1, 8, 10)

  Guest Role
• 
  Bae Seong Il

  [Chief royal secretary] (Ep. 1, 13)

  Guest Role
• 
  Lee Jun Hyuk

  [Crown Prince] (Ep. 1, 3, 5, 10, 13-14)

  Guest Role
• 
  Jo Kwan Woo

  [King] (Ep. 1, 8-12, 15)

  Guest Role
• 
  Park Choong Seon

  Sim Tae Son [Hongmungwan director] (Ep. 2, 6, 8-13)

  Guest Role
• 
  Son In Yong

  [Left Chungcheong province official] (Ep. 3)

  Guest Role
• 
  Jo Deok Hee

  [Tae Seo's friend] (Ep. 3)

  Guest Role
• 
  Lee Jae U

  [Tae Seo's friend] (Ep. 3)

  Guest Role
• 
  Jang Jae Ha

  Ra Yi Eon [Young] (Ep. 3)

  Guest Role
• 
  Hong Dong Young

  [Young Crown Prince] (Ep. 3)

  Guest Role
• 
  Choi Seong Hyuk

  [Bandit] (Ep. 3)

  Guest Role
• 
  Baek In Kwon

  [Bandit] (Ep. 3)

  Guest Role
• 
  Seo Dong Oh

  [Bandit] (Ep. 3)

  Guest Role
• 
  Seo Young Sam

  [Park Seung's servant] (Ep. 4)

  Guest Role
• 
  Lee Kwang Ik

  [Local official] (Ep. 4)

  Guest Role
• 
  Kwak Myung Hwa

  [Beef customer] (Ep. 4)

  Guest Role
• 
  Jo Ji Hyun

  [Beef customer's servant] (Ep. 4)

  Guest Role
• 
  Jo Ah In

  [Child slave] (Ep. 4-5)

  Guest Role
• 
  Uhm Tae Yoon

  [Child slave] (Ep. 4-5)

  Guest Role
• 
  Ha Seung Jin

  Ba Hwe [Tail island] (Ep. 4, 7, 9, 12)

  Guest Role
• 
  Ji Heon Il

  [Servant] (Ep. 5, 7)

  Guest Role
• 
  Jang Tae Min

  [Magistrate] (Ep. 8)

  Guest Role
• 
  Park Gi Seon

  So Ra Bom (Ep. 8)

  Guest Role
• 
  Yang Hee Kyung

  Madam Jo [Yi Eon's grandmother] (Ep. 8, 10, 13-14, 16)

  Guest Role
• 
  Uhm Tae Ok

  [Herb seller] (Ep. 9)

  Guest Role
• 
  Cha Hak Yeon

  Choi Seung Yul (Ep. 9-11, 13-14)

  Guest Role
• 
  Oh Kyung Hwa

  [Deok Bong's helper] (Ep. 9-10, 12, 14, 16)

  Guest Role
• 
  Lee Sung Il

  [Fabric seller] (Ep. 10)

  Guest Role
• 
  Jeon Jin Oh

  [Con man] (Ep. 10)

  Guest Role
• 
  Lee Si Young

  [Noble lady chatting] (Ep. 11)

  Guest Role
• 
  Sim So Yeon

  [Soo Ryeon's mother] (Ep. 11)

  Guest Role
• 
  Hong Suk Bin

  Na Yong Gyun [Royal physician] (Ep. 11, 14)

  Guest Role
• 
  Kim Min Che

  [Jo Yi's tailoring client] (Ep. 11, 16)

  Guest Role
• 
  Ryu Si Hyun

  [Deok Bong's helper] (Ep. 11, 13-16)

  Guest Role
• 
  Choi Gyo Shik

  [Homeowner] (Ep. 13)

  Guest Role
• 
  O Gyu Taek

  [Butcher] (Ep. 13)

  Guest Role
• 
  Gi Hwan

  [Official] (Ep. 13)

  Guest Role
• 
  Park Ji Ye

  Kkot Dan (Ep. 13-14)

  Guest Role
• 
  Park Ji Won

  [Fabric seller] (Ep. 14)

  Guest Role
• 
  Park Eun Young

  [Restaurant owner] (Ep. 14)

  Guest Role
• 
  Kim Moon Ho

  [Restaurant customer] (Ep. 14)

  Guest Role
• 
  Jo Eun Sol

  [Dumpling customer] (Ep. 16)

  Guest Role
• 
  Kim Zio

  [Dumpling customer] (Ep. 16)

  Guest Role
• 
  Hwang Yun Seon

  [Eunuch] (Ep. 11)

  Guest Role
• 
  Jun Sung Won

  [Maeng Soo's soldier] (Ep. 5)

  Guest Role
• 
  Baek So Hyun

  Soo Ryeon (Ep. 11)

  Guest Role
• 
  Moon Hyeon Jeong

  [Dress seller] (Ep. 4)

  Guest Role
• 
  Myung Seok Geun

  [Relay station officer] (Ep. 5)

  Guest Role
• 
  Lee Wang Soo

  [Relay station officer] (Ep. 4)

  Guest Role
• 
  Ko Dong Hyoung

  [Pebble]

  Guest Role
• 
  Moon Sung Bok

  [Crown Prince's guard]

  Guest Role
• 
  Lee Chang Won Guest Role
• 
  Kim Jin Ok

  [Restaurant owner] (Ep. 6, 8)

  Guest Role

Unknown

• 
  Lee Ji Yun Unknown
• 
  An Jun Seo Unknown
• 
  Lee Ru Da Unknown