‘Sung-jin’, who is about to make his debut as an orchestra conductor in Korea, falls in despair when his fiancé ‘Su-yeon’, suddenly tells him that she is leaving him and disappears. 
Su-yeon’s mother ‘Hae-yeon’, the orchestra director, introduces Sung-jin to a substitute cellist, Su-yeon’s junior ‘Mi-ju’, whom Su-yeon had made prior engagements to fill in for her before she left.
After Mi-ju’s audition and spending more time with her, Sung-jin is drawn to Mi-ju’s charms that are the opposite of Su-yeon’s and has a love affair with her. 
Meanwhile, someone watches Sung-jin and Mi-ju through the full-body mirror on one side of Sung-jin’s bedroom.
A man and woman in a forbidden love affair, the hidden secrets surrounding the three and their dirty desires are unveiled.