Caillou must learn to help people in need when he realizes his friend Penny isn't cheerful or happy at all.

Caillou and Penny have always been the best of friends, and with the town's friendship festival being hyped up, both are just as excited as everyone else, to show just how much Caillou appreciates his best friend, he draws a picture of him and Penny, however, when Caillou delivers the drawing to Penny, he discovers something harmful Penny has been doing to herself in secret, it soon becomes an emotional roller-coaster, as the two try and make everything better, they start to realize this could be a permanent end to their friendship.