Luan met Jul for the first time on a snowy day through his terrace. He was impressed by the lonely image of Jul smoke outside with just a light sweater on. One day, Luan’s cat went to Jul’s house through their adjacent terrace and it’s how they official knew about each other. How Luan would get involve in Jul’s introverted life? What is the complicated relationship between Luan, Jul, and Yisun?