While paying respects to her late father, Zian discovers a photograph of him with a young boy named Zitong, whom she doesn't recall. Intrigued, she delves into uncovering Zitong's identity, questions surrounding her father's death, and the mysterious figure shadowing her.

This movie tells a story of young people from 'Ant tribe' in Beijing. By telling the story of these young people, Today and Tomorrow shows the psychological changes of college graduates. It reflects their confusion about future and love. The movie chooses 'Ant tribe' to show a unique aspect of the Chinese society. It encourages all the young people facing problems to learn from the 'Ant tribe' spirit and strive for a bright future.