Undercover High School (2025)

Top NIS agent Jung Hae Seong is demoted after a failed mission and sent undercover as a student at Byeongmoon High School to track down King Gojong’s missing gold bars.

There, he meets Teacher O Su A, a passionate history teacher. But as she gets to know him, she begins to see glimpses of her first love—a love that left a deep scar on her heart.

As secrets unravel and past wounds resurface, will Hae Seong complete his mission, or will his heart lead him down an unexpected path?