Childhood friends Choi Jong Hun and Park Yu Na are childhood friends. However,at the age of 7,they were separated as Choi Jong-Hun left to America due to his father's business. After her childhood friend left, a roller-coaster series of events turned her life upside down. In addition to a shocking incident,her abusive father began hitting her mother and later divorced her mother. This left her family having little to spend. Lee Yu Na stirred a feeling of hatred towards guys and learn taekwendo in order to protect herself against the boys.

When 16 year old Choi Jong Hun returned from America to South Korea,they find themselves together in the same class. Choi Jong Hun was taken aback by the change that Lee Yu Na have developed but never did he forget his feelings and promise to Park Yu Na. Determined to return back to Lee Yu Na at any cost, he trys finding methods to get her back.

Meanwhile,his best friend and fellow band mate, Lee Hong Ki objects his chase. The main reason is because his young sister have a huge crush on Choi Jong Hun and the very fact that he is chasing Lee Yu Na makes it impossible for Hong Ki's sister to fall in love with him.

Wills her heart melt for Choi Jong Hun and past hurts would vanish? Or would cheeky Hong Ki gets his way and separate the couple from loving each other?