Albert Millaud

Denise de Flavigny, a young convent student, discovers a double-life of the organist Célestin, who teaches her music at the convent. He secretly composes popular operettas for his mistress Corinne. Célestin visits the city to witness the premiere of his latest effort; Denise escapes the convent as well. Following a quarrel with Célestin, Corinne walks out and instead, Denise appears in her role, taking the name Mam'zelle Nitouche. Denise falls in love with Fernand, a handsome young soldier. Both Denise and Célestin are mistaken for soldiers absent without leave and shipped off to an army camp. A series of coincidences brings happiness to all concerned.

In an all-girls boarding school, one of the students resists the will of her uncles to marry her off because she does not know her future husband. Which is why she pretends to be a prude for whom marriage is a dirty word.