Choi Sulli a simple 16 year old girl longing for her mom bumps into xi luhan who is a transfer student and also her 5 year old playmate...Luhan is a son of the owner of the national statistic of seoul.... On the later part...Luhan must go to China because of the demand of his father leaving sulli alone in the dark again.... Sulli felt really dissapointed and has mixed emotions against luhan..... let's see how their story works