Castella, portrayed by Jean-Pierre Bacri, is the owner of a steel factory who learns that to conduct business with a group of Iranians, he needs to improve his English skills. To facilitate this, he hires Clara, played by Anne Alvaro, to be his tutor. Meanwhile, Castella's wife, Angelique, an interior decorator with a fondness for her dog, is busy redecorating her sister-in-law's apartment.
During a trip to the theatre to watch their niece perform in a play called Bérénice, Castella, along with their driver Bruno and his temporary bodyguard Franck, spots Clara, who moonlights as an actress. The viewer learns that Franck has a tumultuous past as a police officer; after a troubling case involving a corrupt system caused him distress, he chose to leave the force.
Bruno is sent by Franck to a bar to fetch cigarettes, where the barmaid Manie reminisces about a past encounter with him, though he disappointingly can’t recall her. After Bérénice, Clara goes out with friends, revealing her fear of never getting work again as she approaches forty. Thus begins an unexpected journey for Castella, who, initially dismissive of theatre, becomes enthralled by Clara's artistic lifestyle.
He starts attending her performances and even shares a meal with her friends, yet his lack of cultural sophistication often leaves him the butt of their jokes. Clara candidly tells Manie that Castella is not too bright, despite his attempts at improving his English. His skills progress, moving their lessons from the office to a cozy English tea room. After crafting an awkward poem for Clara, he is taken aback when she divulges that she doesn't reciprocate his feelings.
A day arrives when Clara waits at the tea room, and Castella fails to show up. Meanwhile, Bruno practices his flute, navigating his own romantic struggles as his fiancée in the U.S. has found another partner, bringing strain on their relationship. Manie and Franck, having begun a passionate fling, flirt with the idea of marriage, but tension over her involvement in drug dealing threatens their bond.
As Castella's relationship with Angelique begins to fray, partially due to her disapproval of the art piece he bought from Clara's acquaintance, he becomes frustrated with her decorating choices. Clara, sensing exploitation from her friends towards Castella, expresses her concern. Castella insists his artistic endeavors are genuine, not merely efforts to please Clara.
Franck's contract concludes, and Bruno shares news that his former partner has captured a corrupt politician after all. This realization leads Franck to confront Manie, though he hesitates to reconcile as she watches from her window. Meanwhile, Clara secures the lead role in Hedda Gabler and invites Castella to attend the premiere. After a tense evening watching her performance, Clara's heart swells with joy upon seeing him in the audience, bringing a sense of closure as she takes her final bow.
