Su Yang is an introverted nurse who lives a simple life. Her life has been very peaceful since she was a child, as calm as a puddle of water. In the autumn of 2003, Su Yang and Yuan Mu met, and their lives became turbulent from then on. She became Yuan Mu's special nurse, and getting along day and night made the two of them fall in love for a long time. But Yuan Mu got leukemia. As Yuan Mu's condition worsened, the two fell in love several times. Finally, in the autumn of 2004, Yuan Mu said goodbye to Su Yang in the maple forest downstairs of Su Yang's apartment. However, their love did not end. Although this love only experienced a cycle of spring, summer, autumn and winter. It's very short but also very long. Their love for each other has already transcended life and death, and they have gone through the ups and downs of their lives, and the passing of time.