Each morning Caillou loves to watch the shcool bus drive by and wishes that he were old enough to ride it. Caillou asks when he can ride the school bus, Caillou's Daddy tells him not unitl his next birthday and shows him when it is on a calendar.
The next day Caillou and Caillou's Daddy watch the bus and Caillou's Daddy sees the that the bus driver is Mr.Washington, the same driver that drove him to school many years ago. He says Caillou that Caillou might be able to ride the bus tommorow if his boss says that it is okay.
That night Caillou draws a picture of a bus. Caillou's Mommy remids him that he might not be able to ride the bus.
The next morning, Caillou and Caillou's Daddy get up early and wait for the school bus. Sarah asks Caillou if he is going to school Caillou says he might be able to ride the bus. The bus then comes and Mr.Washington says that Caillou can ride the bus.
After Sarah and all the other students go to school Mr.Wahington takes Caillou back to his house. Caillou's Daddy is waiting for him. Caillou gives Mr.Washington the picture of the bus and Caillou and Caillou's Daddy say thank you and Mr.Washington says he'll see Caillou after his next birthday.
- Caillou never has his next birthday, he is always 4 years old.
- It is possible Caillou has turned five during the series, but hasn't gotten out of playschool, (Not suggesting he flunked, but he might still have a couple more months in it).