毎日楽しく暮らしているミミちゃんとパパンダとコパンダのもとに、サーカスからトラちゃんがやってきた。
ミミちゃんは、トラちゃんをはじめサーカスの人々と仲良くなり、サーカスに招待された。ところがその夜はものすごい雨。朝、起きるとあたりは一面、洪水のため湖のようになっていた。
そして、サーカスの動物たちが水のため困っていることを知ったミミちゃんとパパンダとコパンダは、ベットをボートにして、動物たちの救出に向かった。

Along the way, they befriend a tiger, who has lost its way from the circus. Eventually the tiger finds his way back but only after being involved in several mishaps with Pandy.
Then they encounter a fierce storm which floods the neighborhood. A SOS message is received from the tiger, who is trapped inside a train with the rest of the circus animals, because of the storm.
They rush to the rescue of their distressed friends. Papa Panda braves the foul weather and tears the roof off the train to free the trapped animals. However, in the midst of doing so, the train suddenly takes off and heads towards the town, out of control.
The townspeople all panic as the train is about to crash into their homes. But their fear is put to rest as Papa Panda succeeds in stopping the train in the nick of time and saves them all from a sure disaster.