It's 1993, a twin was born in a hospital in Seoul. 

The parents called them Sooyeon and Jiyeon.

A few days later in the hospital was Sooyeon gone.. 

The family looked and searched everywhere, even the police couldn't find her.

19 years later.. 

A girl named Jessica, who was really famous in the US, was moving from the US to Seoul for some rest and study.

Jiyeon was old enough to live alone with some friends of her, she is studying in a famous school of Seoul, she can dance and sing.

Jessica- looks cold from the outside, but is really lovely on the inside, she's famous in the U.S but later decided to move to Korea for her study and some rest. She is grown in an American rich family. Her heart is really weak, her surgery didn't help, so she can't run too fast, and she can't get tired, her heart will stop beating if it's going wrong.. Jay is the person who loves Jessica, but Jessica is scared to love him, she is scared to be left alone. She is the twin sister of Jiyeon, but they really don't look like eachother.. Will she discover that Jiyeon her twin is?

Jiyeon- also looks cold from the outside, only to people who are close to her know her real personality, Zelo is her boyfriend, and she really loves him, her parents died in a car accident when she was 11, she had picture of her twin and her, she discovered she has a twin, but never went looking for her.. But then she met Jessica.. 

Tiffany- Tiffany is a warm hearted girl and is in the girl group JeTiHyo along with Jessica and Hyoyeon, she always knows what to do, she is the second manager of her own group. She is Jessica's best friend along with Hyoyeon and moved together to Korea. She likes T.O.P

Hyoyeon- likes dancing and is the one of the best dancers in the U.S, She moved to Korea with JeTiHyo, and later she's gonna like Henry.

Yewon- is a lazy girl who don't like school, she lives together with her friends Luna, Jiyoung and Jiyeon, later will JeTiHyo move in to their crib as well.

Jiyoung- is not lazy but loves sleeping, sometimes she is sleepwalking, so she wakes up at random places, Daesung is her boyfriend, they get into a fight really often.

Luna- is a nice cute girl with a beautiful voice, she always try to help people, she is in love with Onew.

I talked to much.. now the story begins!