She has beautiful pale skin and white hair. Seorin has a very cold and calm personality. She is somewhat interested in the protagonist and has many female friends. Since the protagonist is ranked 1st in the entire school, she is ranked 2nd. She is 175cm tall, always eats jelly, and only wears white clothes. She eats ice cream every day on her way to school. She is a high school junior, in the same class as the protagonist, and is his desk mate. She treats everyone coldly. She does not know Kim Hayeon. She is Baek Serin's older sister.

Baek Seorin's younger sister. She looks exactly like Seorin and has the same personality. Her only friend is Kim Hayeon, and she ignores Seorin even when they see each other. She is a high school freshman and in the same class as Kim Hayeon.

The protagonist's younger sister. She hangs out with Baek Serin, whom she became close with after entering high school. She is the prettiest girl in school with 100k followers on Instagram and 150k on TikTok. She has many friends, is very energetic, and plays harsh pranks on the protagonist, like throwing water balloons. She is a high school freshman in the same class as Baek Serin. She does not know Baek Seorin.