Meet Caillou, the lovable 4-year-old with a big imagination! Caillou experiences all the wonders of being a child that audiences around the world can relate to: first day of school, caring for a pet, learning a new sport or spending time with family. Preschoolers feel right at home with trusted pal Caillou, his sister Rosie and all their family and friends as they experience the everyday adventures of childhood. Caillou. Less -