Moonbyul is a very famous solo artist in her 12th year of career. Suddenly a woman accuses her of bullying during their school days. The person affirms that the artist did something on a specific school festival date 14 years before and Moonbyul can't defend herself because she would have to expose the person who was with her. Solar, a multi-talented singer and actress, watches the news and struggles between her animosity towards her former schoolmate and the necessity

Moonbyul and Yongsun' were In love but the first one chose her career over personal feelings. Yongsun wanted to have a family. So she moved on from idol business and built her life. Five years later, Yongsun watches the news about the idol Moonbyul being in a plane crash and she gets desperate. Yongsun's husband doesn't like her reaction. And things will become more tense when Moonbyul is found alive and wants to speak with her ex-girlfriendd.

That is a very expensive and traditional boarding school for girls.  Moonbyul, Yongsun, Wheein, Hyejin and many other girls come from very different family backgrounds. The first one is the co-leader of a group of girls who are copied by others and feared. The new students  Yongsun and Seulgi soon realize things are not what they seem. What is behind Irene's and Moonbyul's cold actions?