Caillou is a clever four-year-old who learns life – the greatest adventure of all. From his own street to the first time he travels by plane - Caillou discovers how exciting it is to be a little boy in a big world. Every day is full of surprises for Caillou. Sometimes his curiosity leads to quite a mess – but all it really does is make him even cuter! And every mess is an opportunity for another adventure... The show is based on a popular book series about a boy named Caillou. The character of the adorable boy has been created by Canadian educationalists and psychologists.