Caillou and the gang celebrate a number of different events, while the puppets are busy going about their business. Gilbert is trying to write an ode to a daisy, but can't think of anything that rhymes with "great elation." Teddy looks to be busy preparing some kind of fesitivity and Rexy's just around moping that Caillou is away and all of the other puppets seem to be too busy to play with him.
Caillou gets up early because he's eager to receive an invitation in the mail to his friend Xavier's birthday party. The mail comes, but Rosie is also up and about and she snatches Caillou's letter and none of the rest of the mail, making it look like it didn't show up. Then Rosie appears with the letter and they realize what's happened. The letter mentions a pinata and Mom tells Caillou there's a special surprise inside the pinata. Caillou wants to know what it is, but he can't find out... until the party.
Caillou feeds Gilbert and then goes looking for him outside. But the cat that comes in isn't Gilbert, but rather his friend Sarah's cat, Ollie. He goes to Sarah's to return Ollie and it turns out that Gilbert was over there trying to eat Ollie's food. Meanwhile, Sarah has a special guest at her house, her cousin Lee-Wun. They're celebrating Chinese New Year, the Year of the Tiger and ask Caillou if he wants to join them. The offer is made tempted when he's told that he'll get to see a dragon, but Caillou's not so sure.
It's Caillou's birthday, and he's hoping for a particular special dinosaur. His grandma gives him a present. He opens it. It's a t-shirt with a picture of the special dinosaur on it, but no special dinosaur. Caillou's upset by it. The guests arrive, and so the play some games. Soon, it's presents opening time. Caillou opens the gifts, but no special dinosaur. Caillou's parents points out to Caillou that he missed a box. Caillou opens it, and it's that special dinosaur Caillou wanted. Caillou is happy.
After Grandma tells Caillou that Grandpa was too sick to have a party on his birthday, Caillou is in disbelief. He decides to throw a belated birthday party for Grandpa and Rosie helps.