Kwon Yul, Choi Youngsoo, Kim Hyo, and Kim Taeng had a deal that Yul should get a “yes” from Yoona in just three days, but it was just a playful deal at first. What if Yul truly fall in-love? Would he also be able to see and show Yoona's true self, the warm-hearted girl that she really is?  Characters: