Bumba is a somewhat naughty, but always cheerful clown who performs his tricks in a circus full of sound and color. He gets help from his best friend Bumbalu, while the bird Kiwi, the bear Nanadu, the elephant Tumbi and many other colorful figures also join in the fun. In their circus, Bumba and the others experience short adventures and situations that are very recognizable for the little ones.

It's Plop's birthday and that, of course, has to be celebrated. Kwebbel, Klus and Lui send Plop into the woods for a long, relaxing walk so they can prepare the party in the meanwhile. But won't Kwebbel talk too much? Can Lui stay awake long enough to help? And won't Klus' new invention cause problems? Let's hope it all goes well..