Undercover High School

Ace NIS agent Jung Hae-seong is demoted after a mission failure. He goes undercover at a high school to locate King Gojong's missing gold, meeting his teacher Oh Soo-ah, who sees him as her lost first love, stirring old heartbreak.

• 
  Seo Kang-joon

  Jeong Hae-sung
• 
  Jin Ki-joo

  Oh Su-ah
• 
  Kim Shin-rock

  Seo Myung-ju
• 
  Kim Min-ju

  Lee Ye-na
• 
  Yoon Ga-i

  Park Mi-jung
• 
  Kim Young-ah

  Im Chung-ha
• 
  Lee Hyun So

  Han Seung-jae
• 
  Yun Chae-bin

  Yun Chae-rin
• 
  Kim Sun-min

  Ji Hyeon-jun
• 
  Kim Seung-beom

  Kim Ho-jin