It happens in SM high school. Our characters are in their first year of high school. Victoria, Luna, Krystal, Amber, Luna, Sulli have been classmates for years. They are like family, always by each other side. They were queens in their old school. They are called as f(x), flowers of X. People love their beauties, cuties but also scared their powers, their evil-sides. These girls were monitors of their old school. Despite their evil-side, people respect them because they lead them well and they are also talented.

So as Changmin, Onew, Taemin, Henry, Minho. They has been classmates for years. They are like family, one for all and all for one. People love them because they are handsome, talented. Of course, they have evil-side too, a lot. They are also monitors of their old school, and they did such a marvelous job.

Cupid does his job: he matches 5 handsome boys with 5 beautiful girls. Yes, at high school they are in a same class, class A.