Song Sarang's parents have an arranged marriage for her, with a boy she's never met by the name of Byun Baekhyun. Eager to make her parents happy, she tries her best to make the best of the situation. Afraid that the boy might not approve of her true nature as an outgoing, loud girl, she struggles to keep a calm demeanor around him. When Baekhyun is sent to her high school to spend time with his fiance to be, the two must keep the secret of their engagement. But what happens when Sarang falls for Baekhyun? And will Baekhyun ever break down her walls and get past her quiet, calm, emotionless demeanor? Will he reject her once he finds out her true nature? And will any of the classmates find out?