Shao Dong, a 17-year-old boy who suffered from lung cancer, was declared by doctors to have only two years left to live. In the countdown to life, he unexpectedly met the 20-year-old heroine Xin Nan on social software. The two gradually established a deep relationship through communication in the virtual world, and finally established a romantic relationship. A year later, in late autumn, Shaodong, who had just turned 18, crossed the mountains and seas and came to the city where Xinnan was located. During this time stolen by fate, they embraced short-term happiness like ordinary lovers - strolling on the street with fallen leaves, sharing oden in a convenience store late at night, and writing unspoken thoughts in each other's palms. When the fifth season came quietly, Shao Dong's condition suddenly worsened. In order to prevent his lover from witnessing the withering of his life, he chose to leave quietly on a hazy moonlit morning. Before leaving, he entrusted his medical records and chemotherapy bracelet to the heroine's best friend Li Xingmian, and left his final instructions in a trembling voice: "Please protect her smile for me." This is a story about the protagonist Shao Dong and the heroine Xin Nan. Shao Dong got lung cancer at the age of 17 and only had two years left. Later, he met the heroine on social media, fell in love, and met happily a year later. Later, the hero disappeared due to physical reasons. Finally, he told the heroine's best friend Li Xingmian and the hero rushed to the fifth season.
