Enter Lee Sun-jae (Yoo Ah-in), a 20-year-old prodigy who works as a bike courier. He has the hands of a concert pianist but none of the privilege. When Hye-won discovers him playing Chopin’s Étude Op. 25 No. 11, known as "Winter Wind," her cold, calculated world shatters. What unfolds is not just a physical affair but a spiritual awakening.