Jean Dezert is a melancholy individual who, plagued with a terrible lack of imagination, is mortally bored. He had begun resigning himself to his own mediocrity when, one Sunday, trying to distract himself, he does what the advertisements he is handed on the streets tell him to do: he takes a hot bath with a massage, has lunch at an anti-alcoholic vegetarian restaurant, and ends his day by attending a conference about sexual health livened by a soiree. It is then that he meets the lively and wild Elvire Barrochet, who approaches him in the middle of the Jardin des Plantes and makes his life impossible. "Jean Dezert es un individuo melancolico que, aquejado de una falta atroz de imaginacion, se aburre mortalmente. Ya empezaba a resignarse a su propia mediocridad cuando, un domingo, como para intentar distraerse, decide seguir los consejos de los folletos publicitarios que le entregan por la calle: toma un bano caliente con masaje, almuerza en un restaurante vegetariano antialcoholico, y finaliza la jornada asistiendo a una conferencia sobre salud sexual amenizada con una velada musical. Es entonces cuando aparece la pizpireta y alocada Elvire Barrochet, que le aborda en pleno Jardin des Plantes para hacerle la vida imposible."