Little Mo is celebrating her birthday with friends and family when she opens the gift her parents gave her. Little Mo is immediately disappointed when she opens the box to find ugly, caterpillar-like creatures squirming around. Although her parents try to explain that they are silkworms who can produce beautiful things, Little Mo refuses to listen. Her friends try to cheer her up with an ensuing adventure in the woods—which involves magic mulberry trees, a mysterious trap and a chance encounter with some silkworms—during which Little Mo realizes that she completely underestimated the gift her parents had so thoughtfully given to her. Feeling grateful for her gift and the incredible skills of the little silkworms, Little Mo quickly realizes that they are actually the best birthday gift she has ever received.