“LEAVE ONE DAY,” a bittersweet musical about “the one that got away,” opened this 78th Cannes Festival. Cécile (singer Juliette Armanet) was poised to fulfill a lifelong dream by opening a gastronomic restaurant in Paris when her father has a heart attack. She’s forced to go back home to spend some time with him, helping in her parents’ restaurant, a pit stop affair that serves French cooking to truckers. Their relationship is tenuous, her father resenting her for leaving her birthplace for the capital.

Already in a romantic relationship with her restaurant associate in Paris, while in the village Cécile runs into a high-school friend, the incredibly charismatic and attractive Raphaël (played by Bastien Bouillon), and flirts with the idea of become involved with him. For real, this time (Cécile was his high-school crush, it is revealed soon that he never got over her). This being a film musical, many of the scenes seamlessly break into dance numbers set to original but revisited French top forty songs whose lyrics everyone in France will know and others, elsewhere, will hopefully vibe to a little. I very much enjoyed this film, it’s sad, funny, there’s music, and the main role, Cécile, stole my heart with her coy smile and ability to show loads of emotions. Juliette Armanet, the actress who plays Cécile, is a highly-popular singer in France, who reminds one of Mylene Farmer and Celine Dion.

The opening film at Cannes has often been a blockbuster, “THE GREAT GATSBY” in 2013, “FURY ROAD: FAST AND FURIOUS,” more recently. Name auteurs have also appeared in this high-pressure slot, Woody Allen did so in 2013 for “CAFÉ SOCIETY” and Wong Kar-Wai’s “MY BLUEBERRY NIGHTS” was shown on opening day in 2007.

That “LEAVE ONE DAY” (“PARTIR UN JOUR”) was the opening movie this year is a novelty. It’s a French film by an unknown director and it has popular French music whose lyrics only people in France will know, and by heart. It’s also a movie by a woman director, only the fourth one in the opening film slot in all of the festival’s history.