---CHARACTERS---~Park Jiyeon~ ---A sweet and bubbly girl. Jiyeon has been studying in Seoul University, one of Korea's top schools, she's not popular, she's the kind of person who is contented with what she has. Jiyeon is mostly quiet and shy to people and doesn't really talk to people whom she just met.

This story circles around the lives of Suzy,Jiyeon,Krystal,Sunny and Hara, five girls whose clique falls apart after the disappearance of their friend Yoona. Months later they begin recieving messages from a mysterious figure using the name "Y". At first they think it's Yoona herself, but after she is found dead, the girls realized that someone else knows their dirty secrets-including long hidden ones that they thought only Yoona knew.  --------------------