When a prank goes wrong on fellow high school classmate, Kim Ryeowook, popular, rich, but rebellious Choi Minho has to suffer the consequences.  

Ruining his family name, he is soon forced by his father to do community service around Seoul. Because of this, Choi Minho has no other choice but to interact with the shy, poor, yet smart Choi Sulli, a girl he's always seen around the school but to whom he has never spoken to. Their different social statuses has always left them worlds apart, despite always being physically close in proximity.

The annual city play is then expected to be held and unfortunately for Minho, his final duty to complete his community service is to play the role of the lead character.

When Minho needs assistance in memorizing his lines he decides to ask Sulli for help, who works as a stagehand but is the only other person he knows working on the play. At first Minho only uses Sulli and treats her coldly when his other friends are around. But as they spend more and more time together, their thoughts about each other begin to change, as well as their feelings.