"Your My Blue Moon..Don't you understand? Your my everything..I can't get you out of my head...All I can think about is you..Your lips, The way you look at me, How you run your fingers through your hair when your frustrated or bite your bottom lip when your nervous..Your my muse...The reason why all my songs revolve around you..Your my heart, And without you..I don't think I can do this...I can't keep going without telling you how much I love you..So please don't go...Be Mine."  

Thisis just a random story about a boy who wishes to be with the girl he loves this April Fool's Day. He's like the other guys who are afraid to tell the girl they love their feelings.        

Was it really just pure coincidence? A story when they met and fell in love but they are too proud to admit it. Will their love story blossom?

Im Yoona who wants to change her life, met Lee Jonghyun who passionately in love with music, her old classmate. Yoona had no idea at all that she was Jonghyun's first love when they were just a high schooler. They want to change their life by spent time together, and slowly, they're calling back their sweet memories they've spent together.