The heroine Lin Xia discovers a confession paper airplane that was not sent out in 2015 in the old school building, and recalls the youthful story of her crush on Lu Chen in school. When they meet again ten years later, Lu Chen reveals the truth about her unresponsiveness, and Lin Xia feels relieved and sends out the paper airplane, symbolizing the regretful end of youth.
Purpose: The novel uses paper airplanes to connect youth and reality, sublimates personal emotional stories into philosophical thoughts on "regret and growth", and encourages readers to accept the imperfections in life through healing narratives and gain spiritual freedom through relief and reconciliation.