Krystal is a queenka of SM high and all the BOYS like her. But she has boyfriend named Choi Minho. Her sister, Jessica Jung, decided to make her a normal girl back as she is a nerd. So she ask help from Lee Taemin who is abit poor. And he started to stay with Krystal and he changed to her school too. But Taemin met someone who is important for him once, Choi Sulli. will he like Krystal or go for Sulli back?