Ha-soo since she was young has had a long term crush on her best friend, Set-byeol, but she's satisfied with her current position as her best friend. Ha-soo, who thinks that she knows everything about Set-byeol, knew that she always liked someone as whenever she was asked out, she gave the same response, "I already have someone I like.", so she didn't give it much thought. But Ha-soo's mind becomes anxious when she sees her close, face-to-face with a boy in class after school.