Four children who grew up together became cautious because of an accident. Bai Qiaochu's amnesia and Xia Monan's death made a person live in the heart of every living child. Lu Yanqing's intentional intervention caused the three childhood friends to quarrel endlessly. Xia Mobei's fear and Xun Xun's accidental fall down the stairs brought everything back to where it started. When everything calmed down, when Bai Qiaochu thought of the beautiful scene that day, it felt like a lifetime ago. She was glad that they were still together.