Jaehee appears to be a reserved and diligent high school teacher, but her true passion is kneeling before a whip behind closed doors. Her childhood friend, Huilin, is the one who relishes wielding the whip. However, secrets and emotions that have been buried for a long time begin to resurface when Sulhwa becomes a student-teacher at the school. Jaehee will soon discover the extent to which she can derive pleasure from pain.