Today, Langlang takes a boat with his mother to the fishing village where grandmother lives. The young boy has just turned six. He will start school tomorrow to learn to read and write, and also to make friends. That's why Grandma wants to give him a very symbolic present.

Pierrot has a stone on his back. He doesn't know why he has to carry it, but for as long as he can remember, the stone has always been there, on his back. And he is not the only one; with his two brothers Pi and Po, Pierrot lives in a peaceful kingdom where everyone carries a stone on their back. Until the day when he has to cross the river to save the princess...