Yoon Im is a blunt but talented Korean language teacher at Daechi Dong Academy. On the day of the midterm exams at her middle school, Ki Haeng, the school's language teacher, visits her. When the two meet, the parents of Daechi Dong begin to gossip and suspect that the test questions have been leaked. Yoon Im's encounter with Ki Haeng brings her face-to-face with the past of her college days, which she has been trying to forget, including her novelist and best friend, Na Eun, her ex-boyfriend from ten years ago, Ki Haeng, and her crush, Michio.