In the countryside of France, two groups of boys from the rural villages of Longeverne and Velran are in constant war against each other. Their war is a tradition that passes from father to son and without a motive but the rivalry between the peasants. During the Second World War, the Longeverne boys are led by the intelligent William Lebrac, who has been the backer of his family since his father died, while the Velrans are led by the wicked Aztec. The boys are frequently fighting with their wooden swords, throwing rotten fruits or building traps in the woods expecting to remove the buttons from the enemies' clothes. But Lebrac is coming of age and he has a crush on the girl Lanterne while his teacher Merlin offers the chance for him to have a better study in another village.