Jean is a 9 year old orphan who wanders in Paris and sells small wood headstocks which he himself makes. His life is changed when he meets D'Artagnan. He is the first to offer him hospitality on his boat moored on the Seine. Both will become inseparable and his agility will save D'Artagnan from many mistakes! Moreover, he is a perfect handyman who manages to create all kinds of inventions and very useful gadgets.

Jean is not completely orphan because he seeks his mother, Catherine. He was separated from her when he was 3 years old.