1x7 - Undercover High School

Hae Seong is caught off guard when he recognises Su A's childhood name, Bong Ja, which stirs memories of his first love and distracts him from his focus. Despite the emotional turmoil, Hae Seong pushes forward with the mission to uncover the secrets behind the third ghost story. However, a missing key component forces Su A to join the mission despite Hae Seong's strong opposition to her involvement