Accompanied by his extraordinary confidant, Mimmo, Charley discovers with wonder the small village beside the sea where he's going to spend his summer vacation.
The vacation quickly turns out to be full of rewarding encounters and adventures. Charley shares all the events of his life with Mimmo, the ups and downs, joys and jealousy... His family now has a new member, Fanny, his little sister.
But a mysterious shadow upsets things when it steals the village children's favorite toys. With his new friends, Pilou and Lalou, alongside, Charlie leads an exciting investigation and catches the crook.
After much emotion and fears overcome, all ends well, with fireworks and a concert in the village square.
Now, that's what it means to grow up!