Su Yu and An Yao's love story unfolds in a modern city. They meet and fall in love, only to break up amid misunderstandings and conflict, their relationship weathering many emotional ups and downs. After Su Yu achieves success in his career, he neglects An Yao's feelings, and their relationship falls apart. After they split, Su Yu realizes his mistakes and tries to win An Yao back. But just as they are about to make things right, Su Yu is diagnosed with a terminal illness. To spare An Yao the pain, he hides his condition and goes abroad alone for treatment, leaving behind a letter full of love and endless regret.
