A big surprise birthday party for Uma becomes more about the party and less about Uma. Uma becomes a little overwhelmed and Grampu, Oobi, and Kako realize that Uma would prefer a small party. They adjust their plans accordingly. — ABC Television (source)
Oobi and Kako are hiding under the table. They wave to the viewers and explain that they're hoping to surprise Uma on her birthday. They hear a knock on the door and think it's Uma. However, it's just Grampu, who walks in with shopping bags. He tells the boys that he bought supplies to make Uma's birthday cake. A few seconds later, Uma walks in behind the boys, surprising them instead.
The next scene shows Uma opening her presents in the living room. Grampu gives her a big present and Kako gives her an even bigger one. Oobi walks in with a gigantic present, which ends up being an oversized teddy bear.
Later on, Oobi teaches Uma how to play the party game "Pin the Tail on the Donkey." Oobi gives her a fake tail and a blindfold, then tells her to put the tail on a picture of a donkey without looking at it. Uma accidentally goes the wrong way and walks through the house with the tail. She passes by the bathroom, interrupting Kako, who was sitting on the toilet. She ends up the kitchen, where she falls into Grampu's unfinished cake. Shocked, Grampu asks if the cake tastes good. Uma says that it's delicious, but she's disappointed that she ruined her own cake.
Oobi, Kako, and Grampu go in the living room to sing "Happy Birthday" to Uma. They start a conga line and dance around. While they sing, Uma tries to tell them something. However, the boys are having so much fun that they don't even notice her.
A while later, Oobi realizes that she has left and searches for her. He finds Uma in her room, where she looks depressed. Uma tells him that the party was becoming more about the activities and less about her. Oobi suggests that they throw a smaller party, which Uma says she'd like. Kako and Grampu walk in, singing "Happy Birthday" in a softer tone. Kako gives Uma a new present, which is revealed to be a smaller teddy bear. Grampu brings in a birthday cupcake and Uma blows out the candle. Uma says that this is the best birthday she has had yet.
Later, Uma spots slices of Grampu's cake on the table and decides to play a counting game with Kako. Uma tells Kako that whenever she counts the slices, Kako will eat one. Kako is excited but ends up eating too much cake. Uma wants to count bowls of ice cream next, but Kako is so full that he faints.
In the next scene, Oobi asks the viewers if they have ever had a birthday party. A few preschoolers are shown talking about their birthday experiences. Oobi explains that birthdays are all about friends and family. He and the others wave goodbye in their party hats, ending the episode.