It's Little Bunny's birthday and he thinks everyone has forgotten. Suddenly he notices a balloon floating by. He chases the balloon to return it to its owner because he's sure it will cheer him or her up. Along his journey, he is aided by friends who help him travel across the land, through the forest, in the air, and over the sea. When he finally catches up to the balloon, he sees a large bunch of balloons at the top of a hill beside his family and friends shouting, "HAPPY BIRTHDAY!"