S4·E26 Deep Sea Caillou

There's a new girl named Lee Wun in playschool, but she's so shy she won't talk to anybody. Miss Martin brings in a fish tank to show the class. After imagining he's a tiny deep sea diver swimming in the fishtank, Caillou discovers that Lee Wun knows a lot about fish! Encouraged to tell the others what she knows, Lee Wun is able to start making new friends.