Kwon Yuri was a normal teenager of 17 years old. She liked reading romantic books and listening to calm musics. She was very talented and a little bit shy. She lived among her "sister" Yoona, the perfect and intelligent school girl. Their relationship wasn't very good.

Jessica (Jung Soo Yeon) was a selfish 17 year old girl. She had a younger sister, Krystal (Jung Soo Jung) with 16 and a cousin who lived with their family, Nicole, with 16 years old too. Nicole's parents were dead, so, Mr. and Mrs. Jung adopted her. Nicole and Krystal spent more time together than with Jessica. Their parents transfered them for a new school, while they were in L.A. Jessica just wanted to be the most popular girl in the school.