After being a highschool student, Jiyoon finally got a boyfriend named Myungsoo.

But, when they're together, Myungsoo's ex-girlfriend, Jiyeon appeared which made Jiyoon really worried. Myungsoo is her first love but too bad she's not first for Myungsoo...

Joy, sadness and disappointment of love will be in this story. What do you think will happen to Jiyoon?