Kim Hyun Joong was a rebellious boy, rich, handsome, cocky. His parents owned the school, so he never got suspended.

On the other hand, Hwang Tiffany was a quiet girl, shy, pretty, sweet. She hated attention and she always sat in the back of the classrooms. 

Put them together, that's one disastrous couple. But hey, opposites attract!

Hwang Mi Young (Stephanie/Tiffany) : Shy and quiet to people she doesn't know, but sweet and caring to those she knows, crazy and outgoing to those she's really close to. Best grades out of the whole classroom school. #1 on exams. Best friends with Yoona.

Kim Hyun Joong : Get-the-heck-out-of-my-way to people he doesn't know, partner in crimes with those he knows, nice and fun to those he's really close to. Smart, but not as smart as Tiffany. His parents own the school. Rich.

Im Yoona : Friendly to people she doesn't know, friendly to those she knows, loud to those she's really close to. She has a secret crush on Hyun Joong, and Tiffany knows that. Best friends with Tiff.