Ji Eun (IU), a very sweet, kind, and clumsy girl attends J Arts High with her bestfriend, Wooyoung. Ji Eun, has a dream of becoming a famous kpop star with talents in both singing and dancing. Wooyoung has a talent of dancing and has the confidence in becoming a star. As they arrived at the school, they bumped into a the most popular guy in school, Taeyang. Taeyang is ranked #1 in singing and dancing and is loved by many. He's like a celebrity in the school, and is already treated like one. Taeyang then gets closer to Ji Eun and starts developing feelings for her. Wooyoung, already has feelings for Ji Eun since the 3rd grade, but she never noticed. One thing about Ji Eun is that, she has heart disease that she's not aware of, which will make things very complicated for her. Who will Ji Eun fall for? Will she be okay with her heart disease? Is her dream going to be successful?