Art graduate student Yu Xing is forced by his professor to spend a month teaching at a rural high school as a substitute teacher in the hopes that the change of scenery will inspire Yu Xing and help him salvage his rejected graduation project. Upon his arrival, Yu Xing meets Xu Lu Hui, a cheerful high school student with a passion for painting but limited opportunities to pursue it. While their initial interactions aren't the smoothest, the two eventually strike up a deal together: if Lu Hui drives Yu Xing to outdoor sketch locations, Yu Xing will give Lu Hui private art lessons outside school hours. As they spend more time together and their bond deepens, Lu Hui begins to develop feelings for his substitute teacher. What will become of this forbidden romance?