With his looks and his talent, Ryu Chanyeong is an exceptional violinist who lacks nothing. Joo Hajin, who admired him from afar, dreamed of performing a duet with him, but reality isn’t so kind. One day, Hajin gets the opportunity to be mentored by Chanyeong. While following him, he ends up overhearing something he shouldn’t have. Before he can even gather his thoughts, Chanyeong offers him a strange deal in exchange for the mentorship. "Let’s be sex partners for a set period of time. When I say it’s over, we end it cleanly. How about it?"