A name, "Chen Mo," suddenly called out at a birthday party tore open a gap in Su Xiaotang's memory. The final six months of senior year had vanished without a trace, leaving behind only the pain of her falling out with Lin Wanxing. As clues emerged in encrypted videos, old paintings, and diaries, the troubles faced by transfer student Chen Mo, the rumors that spread by accident, and the secret plan the five of them made to help gradually became clear. From beneath the old locust tree on their high school campus to keeping vigil outside an operating room years later, reuniting at an art exhibition, and offering blessings at a wedding, six friends spent ten years proving that friendship can fill the regrets of youth. The days they spent together will always be the most precious old diary in their hearts.
