Undercover High School

Jung Hae Seong (Seo Kang Jun) is an ace field agent for the National Intelligence Service. But after an operation goes wrong, he's demoted and assigned to a new mission: locate Emperor Gojong's missing gold bars... while undercover as a high school student. He is sent to Byeong Mun High School, where he joins the homeroom class of temporary Korean history teacher Oh Soo Ah (Jin Ki Joo). The deeper Hae Seong delves into his mission, the more unexpected challenges he encounters – including forming bonds that blur the line between professional needs and personal connections. Making things even stranger, Soo Ah begins to notice striking similarities between Hae Seong and her childhood first love, who left her with deep emotional scars. Will Hae Seong manage to complete his mission unscathed, or will this be his most difficult undertaking yet?