The show begins with H Soong dreaming about her high school sweetheart, Lehman Min, who tragically took his own life. Six years later, Soong is a graduate celebrating with friends. She plans to return to her old high school as a trainee teacher, only to find out her friend J Young has applied to the same school. Soong arrives at Cooy Young High School, reflecting on her past with Lehman Min, only to be startled by a figure resembling him. J Young brings her back to reality.