Like any group, there is a dominant upper class and Lee Eunwoo is a nerd who looks up to them. Seunghye, his best friend since childhood, suddenly feels alienated from him by mixing with them. However, when she meets Choi Heesun, who lives in the upper class, a ray of light begins to shine in her life. After mixing with Heesun, she begins to long for upper-class life, where she meets real people, and searches for Heesun's brother, Choi Bin. "You more.. have potential, you're Lee Geumwoo's little brother."