Yoosu, whose first love is his childhood neighbor, Chungwoo, gets his feelings discovered by Chungwoo's sister, Jiwoo. Jiwoo proposes to the flustered Yoosu that he become her fake boyfriend so Yoosu is able to see Chungwoo more often. But contrary to his initial hesitance about his feelings for the other, after seeing Chungwoo again for the first time in a long time, Yoosu is greedy to get closer to him...