In the serene blue sea, lives a pair of good friends: the great white shark Dazhu and the bamboo shark Paopao. They spend their days swimming among the coral reefs, watching over their fellow shark companions who are about to enter this world. However, greedy humans dive to the ocean floor, recklessly harvesting shark eggs merely to satisfy their appetites. At the same time, unscrupulous modern factories indiscriminately dump wastewater and waste materials, turning the once-blue sea murky and polluted. Dazhu and Paopao each have their own troubles: Dazhu has always fed on tires but now wishes to try new foods; Paopao, witnessing shark eggs being captured by humans, hopes to seek the help of Dr. Octopus to rescue his companions on land. Human destruction of the ocean grows increasingly severe, and the marine animals seem ready to unite to save their home...