This is a story about memories. When she was young, Gu Nai had a simple nature. She thought that friends would be friends for life, and liking would be liking for life. When Xiao Hui appeared in her life that year, his shadow could no longer leave her sight, and the hormones of youth had nowhere to rest. Gu Nai spent half of her life waiting and secretly falling in love, but what she was waiting for was the betrayal of her friends. This unprepared situation once made her confused. But many years later, a huge class reunion completely changed the fate of those intertwined people.