A war photographer and absent father, who spends more time taking care of his camera than his four daughters, enjoys a happy life in the Alps with his new girlfriend. But his life is turned upside down the day that his best friend tries to reconcile him with his family by telling them a big lie.

Set in 1958, Populaire focuses on Rose Pamphyle, who lives with her widowed father and is destined to marry a son of the local mechanic. Rose travels out of town and applies for a secretarial job with an insurance agency run by Louis Échard. Louis learns that Rose can type with extraordinary speed — using only two fingers — and he tells her to compete in a speed-typing competition if she wants the job.