In an all-girls high school, the popular Min Namsu's brightest moment of the day is seeing her best friend Kwon Joy. Her heart races when Joy cheers her on during her running practices, and when Joy snaps pictures of her, intense feeling strikes through her body, making her believe she must be camera-shy. Namsu has heard numerous stories about Joy's childhood friend Lim Hye-yeon, so when Joy shares that Hye-yeon is returning to Korea after years of studying abroad, Namsu is excited for her. However, the moment Hye-yeon steps off the train, she kisses Joy on the lips. The mere sight of the interaction stirs something up inside Namsu, to the point that, despite Hye-yeon's magnetic personality, she cannot bring herself to like her. As Hye-yeon spends time with Joy, she realizes that Namsu harbors the same feelings as she does. Hye-yeon subtly declares war on Namsu for Joy's heart, but Namsu must confront and understand her own feelings and determine how to handle them before she can fight on equal terms. [Written by MAL Rewrite]