Vivacious little Gilberte, known as Frou Frou, is the daughter of M. Brigard, a retired merchant, who has as his companion in a life of gaiety, Comte Paul de Valreas, a much younger man. Both the Count and Henry de Sartorys are in love with Frou Frou, and when De Sartorys asks for the hand of Frou Frou, M. Brigard refers him to Louise, the elder daughter, who is in charge of the household. To Louise, who loves de Sartorys, comes the first anguish of her life, when he confides his love for Frou Frou. However, she confers with her little sister who agrees to marry De Sartorys. Paul also asks for Frou Frou's hand, but Brigard refuses, stating he is too jolly a companion to be trusted as a son-in-law.