Ever since Myungsoo's girlfriend passed away, he never thought of loving anyone again. He was afraid that if he love again, he would lose the person he love just like how he lost his first love. So then he made a promise to Haeyeon his ex girlfriend who has passed away, that he wouldn't love anyone else other than her but then what happens when there's a new student named Park Jiyeon who looks exactly like her? Will he be able to keep his promise or not?