Jaejoong suffers - every night.

He cannot find sleep since horrible nightmares haunt him night by night and make his parents think that he became lunatic. They send him to a mental institution to 'heal' his mind, but noone is sure if Jaejoong can learn to cope with his past.

Fortunately, he hasn't to be on his own:
There is Yunho, an employee of the clinic, who dreams about becoming a famous dancer someday;
Heechul, a selfish arrogant patient with the greatest heart you can imagine;
and Siwon, Mr. Perfect aka 'Prince Charming', who only wants to win the heart of  'Cinderella'.