During his innocent and clueless high school days, Soo-young has the worst first kiss with his first love, Chaeri. Before they can resolve the misunderstanding, Chaeri transfers to another school, and Soo-young buries the unsettling memory of that first love. Years later, after completing his military service, Soo-young attends an opening party and unexpectedly runs into Chaeri, who has transferred to his school as a new student. Shaken by Chaeri's unpredictable approach, Soo-young finds himself having an impulsive first experience. "What if I give you a chance to make up for it?" Chaeri asks. "You started it," Soo-young replies.