Yerin is a normal teenage girl; intelligent, playful, and somewhat nerdy. She isn't the 'best looking girl' back then, her life in elementary school is certainly a tragic time, but Yerin is determine to change when she enters high school. She later finds out that she falls in love with the "white princess" of the school; a nice, honest, loyal, attractive, basically perfect girl that everyone falls in love with. But... She also found herself watching over the "black demon"; heartless, boring, overall the opposite of the white princess.