Yoona, Tiffany, Jessica, Seunghyun, Hyun Joong, and Changmin are only weeks away from graduation.  The girls have fun in their sleepover while the boys are together causing trouble.  Being best friends ever since the first grade, Yoona is encouraged by Tiffany and Jessica to have a relationship with Seunghyun.  Yoona laughs at the thought, but she doesn't know that the sleepover isn't a regular old sleepover.