A boy falls to his death at school, but Ok Chanmi does not believe that her twin brother, Park Wonseok, committed suicide. Chanmi transfers to her brother's school, Yongtan High, and meets Ji Sooheon, who witnessed her brother's death.

Baek Ho-rang is a high school student. Due to her pretty appearance, she is popular on social media and at her school. Yet, Baek Ho-rang only has one friend, due to her condescending personality. Baek Ho-rang encounters a problem. She learns that someone is trying to unveil her secret. To find that anonymous person, Baek Ho-rang joins her high school's broadcasting club. Go Eun-taek is the chief of the broadcasting club. He is a perfectionist and respected by the club members.