Undercover High School

[1차티저] 국정원 요원 서강준, 고등학교에 잠입한다!, MBC 250221 방송

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.