Li Muzi and Lan Qing grew up in Wuling, a small town in the south of the Yangtze River. They were childhood sweethearts and fell in love with each other. They went to the same key high school and were admitted to the same university. Like all young people, they met the right person at the right time and they finally got together! Male talent and female appearance, everything looks so natural, so beautiful, so enviable. However, everything happened so unexpectedly. In their third year together, when they were about to graduate, Li Muzi was broken up! Lan Qing, who said he would love her forever and never leave her, left her without any warning and never looked back! Without the slightest bit of defense, she couldn't accept this sudden blow. Why did you stop the lives of two people first? She almost collapsed! Thoughts were flying, the old alliance and the beautiful moments were replayed in Muzi's mind like a movie... She couldn't figure out why Lan Qing was so determined to leave. On a March day, the night was getting darker, and on the ancient street filled with their beautiful memories, the rain was falling, and Muzi seemed to vaguely see herself and Lan Qing as children...