Chay ordered waterproof invitation cards to be able to go underwater because she is celebrating her birthday. She goes with Jett to the unique Vanuatu submarine post office. Except that fish take the fruit hanging on the letters, risking delaying delivery. Paul and Paul Pet are called in to save the party.
| Creator | Jung Gil-hoon |
|---|---|
| Actor | Moon Nam-sook, Chang Eun-sook, Hong So-young |
| Country | China, South Korea, United States of America |
| Production | FunnyFlux Entertainment |