People come and go. The people we have now with us may just be there temporarily because as they say, the only constant thing in the world is change. People change. They change constantly. Classmates? Friends? Family? There is no assurance that they would be there forever. Someday everyone will be gone. Because change is inevitable and to change is human. 

He pushed her away but she promised to stay.

She is Jung Yunseo, the extraordinary girl who dared to fight for his attention. 

He is Kim Mingyu, the hopelessly cold guy who captured her heart.