Lauren King (Diane Lane) is 13 years old, highly intelligent, and rich. She is an American girl living in Paris who spends her free time reading Heidegger. Daniel Michon (Thelonious Bernard) is 13 years old, highly intelligent, and poor. He is a French boy who loves Hollywood films and who uses his talent with mathematics to make imaginary bets on horse races.
When the two meet and fall in love, Lauren's flirtatious mother (Sally Kellerman) fiercely objects and tries to split the two up. Lauren and Daniel decide to run away to Venice, in order to "kiss under the Bridge of Sighs at sunset while the bells toll", which they have been told will mean that they will be in love forever. They are aided in this plan by Julius (Laurence Olivier), an elderly well-bred pickpocket.
Trivia
The film received two nominations at the 52nd Academy Awards: WRITING (Screenplay Based on Material from Another Medium) and MUSIC (Original Score). It lost the first one to Kramer vs Kramer. Georges Delerue, at the age of 55, won his only Oscar statuette in his third nomination, having been nominated previosuly for his work in Anne of the Thousand Days, The Day of the Dolphin and Julia. He'd received a fifth nomination for his work in the 1985 film Agnes of God.
The film is based on the French novel E=mc2, Mon Amour by Patrick Cauvin. The book has a sequel, Pythagore, Je t'Adore, which picks up several years after the events of the first book.
A Note: Robert Redford is featured in 2 movies throughout the film (Butch Cassidy and the Sundance Kid and The Sting, presented in the Italian as 'Il Stangata'): this may have been due to the director's (George Roy Hill) relationship with Redford, as Hill directed both Butch Cassidy, and The Sting, as well as A Little Romance.