A series of misunderstandings causes Lee Shin (Jung Yong-hwa), the cocky leader of "The Stupid" and Lee Gyu-won (Park Shin-hye), a college student majoring in Traditional Korean Music to start on the wrong foot. Gyu-won does not understand why Lee Shin is so popular, until one day she is forced to go the band's concert with her friends, who are fans of "The Stupid". There, she sees Lee Shin performing live, and is immediately captivated by him.
When Gyu-won decides to join the performance group for the upcoming 100th anniversary performance for the university, everyone sees her potential and talent, particularly Kim Suk-hyun (Song Chang-eui), a Broadway composer-turned-music director. She competes with Han Hee-joo (Kim Yoon-hye), the spoiled daughter of the Chairman, for the role of the leading actress (but lost to her, as Hee-joo had previously bribed the judges). Lee Shin also decides to join the musical due to his crush on the dance professor, Jung Yoon-soo (So Yi-hyun), who is also the choreographer and muse of the musical. As Gyu-won and Lee Shin spend more time together, they began to fall for each other.
Fearing that Gyu-won might outshine her daughter, Hee-joo's mother schemes with Im Tae-joon (Lee Jung-heon), one of the school's administrators; and they plot to destroy Gyu-won's image to force her to quit the performance. Lee Shin works with Suk-hyun in order to clear Gyu-won's name. Meanwhile, Joon-hee (Kang Min-hyuk) struggles between his ever-growing feelings for Hee-joo and helping his friends as she threatens their university lives.
When Hee-joo is found to be suffering from vocal chord infection, Gyu-won is given the chance to replace her and go on stage. However, the kind-hearted Gyu-won chooses to let Hee-joo stand on stage instead, while she sings for her backstage. When the media found out that Gyu-won was the actual singer, she was offered a chance to go overseas to record an album. A new conflict occurs as Gyu-won is made to choose between her dreams and love. At the same time, Lee Shin was suffering from a broken wrist caused by a fall he suffered with Gyu-won earlier. Worried that she might forfeit her dream to stay with him, he lies to her and insists that he is fine, even after crouching in pain during a performance with The Stupid. Gyu-won eventually decides to go to the United Kingdom to fulfill her dream, while Lee Shin undergoes surgery to fix his broken wrist.
|2012||Baeksang Arts Awards||Most Popular Actress (TV)||Park Shin-hye|
|2013||K-Drama Star Awards||Hallyu Star Award||Jung Yong-hwa|
|2013||Asian Television Awards||Best Single Drama||Heartstrings|