Based on the books by Christine L'Heureux, the show centers along a 4-year-old boy named Caillou (the titular character) who is fascinated by the world around him. Caillou lives in a Blue House on 17 Pine St. (As mentioned in the episode "Where I live") with his mommy, his daddy, and his 2-year-old sister, Rosie. Each episode in Season 1-3 has a theme and is divided into several short, attention-holding sections that mix animation, puppet skits, and video of kids in real-life situations. In Season 4-5 episodes, they are divided in 3 shorts instead of 4. In the many seasons of Caillou, Caillou has many adventures with his family and friends. Sometimes things go wrong for Caillou and he can grow very upset. Despite the trouble at the end Caillou is always happy, just like real-life 4-year-olds.