Ryu Chanyoung is an exceptional violinist who lacks nothing—he has the looks and the skill. Joo Hajin, who idolizes him, dreams of performing a collaboration, but reality is harsh. Then, Hajin gets an opportunity to receive mentoring from Chanyoung. While eagerly following him, Hajin accidentally overhears something he shouldn't have! Before he can even process what happened, Chanyoung offers him a strange deal with the mentoring as the condition: "We stay as sex partners for a set period, and when I say it's over, you end it cleanly. How about it?"