These days, Yoona has been a hard working girl, because of her many schedules she can't think clearly. Even to her eonnies, she can't answer them easily thinking of what are her next schedules. One day, she have her dayoff no schedules to go to. Her eonnies know that she really needs it so they leave her to relax and think things through. Then she began to think of someone. Her oppa who always makes her happy when she's stressed out. Who could it be?