A love triangle.
It's as simple as that.

Song Jieun finds herself between two completely different men and she doesn't know who to chose. 
She never thought or believed that a girl like her, someone simple, someone who didn't like to be the center of attention would be in such a position. 
Both men want her love and even thought she loves both of them with all her heart, she knows she can't chose no matter how much they want an answer. 
 

She always believed love was like it was in the movies and books. Something beautiful, perfect and something full of happiness.
Instead, she found out that love was confusing and most of the times painful. She always wished for the most beautiful love of them all, but instead, she was getting her heart crushed by every single breath she took.
 

Kim Sunggyu and Nam Woohyun were complete opposites.
Kim Sunggyu was a rebel. He did everything people told him not to. He entered ilegal bike races, he smoked, he drank just so he could feel something, as he usually said but had the voice of an angel, that not many knew about. He never thought he would fall for somoene like Song Jieun, but when he did, he promised himself he would make her his. He believed that she was the only bit of perfection this horrible world had and he wanted her for himself. He never realized how possessive he could actually become of her.

Nam Woohyun on the other hand was the perfect golden boy.  He was a good son, always a perfect student, wonderful friend and was probably one of the most caring, amazing men that ever crossed this earth. He always watched Song Jieun from afar, ever since he saw her playing the piano. He never imagined he would fall for her. He never believed in love to start with. He always thought it was something that he could live without since he was already loved by so many people. He could live without loving someone so much. Ever since he talked to her, he promised himself he would make her happy. Him and only him.
No other man could make her smile.

Who is she supposed to chose? 
Who is she supposed to love without regretting? 
She doesn't know and is afraid of hurting them. She doesn't care about herself anymore, but she's afraid to break one of those men's hearts.
Those caring, wonderful men that she loves so much.
Sometimes, she believes she should just give up and leave.
Forever.