Sanmao drifts through 1930s Shanghai as a penniless orphan, in a city where people dream of getting rich. He and his bald friend Xiao Laizi unexpectedly receive grain from Wu Zifu, an entrepreneur. Later, Sanmao mysteriously falls into a coma, and a reporter named Hou Yiwen sets out to uncover what ties Wu Zifu to the boy. The story is a comedy built around street life in old Shanghai.