It was Yoon So Yi’s sixteenth birthday, and things were perfectly fine. Just when she thought that nothing could ruin her sweet sixteen, a stranger approaches her! Stealing her first kiss...  To make her life even more complicated, seven handsome guys transfer to the little private school she attends- and she has a feeling one of them took her first kiss! With the help of her cousin, Yoon Ji Min, will she be able to figure out who took it?