1950年代のフランス、マルヌ川の静かなほとり。夢見がちで想像力豊かな子どもフランソワの人生は、父親が庭に船を作り始めたことで一変する。こうして、一家の壮大な旅、彼らをどこかへ運んでくれる船を作るという冒険が始まる…現実と空想の狭間で。

1950’s, France, by the serene banks of the Marne River. François, a daydreaming child of boundless imagination, has his life changed when his father decides to start building a boat in the garden. Thus begins the family’s grand odyssey, a collective venture to construct a boat that would carry them away – somewhere between reality and reverie.