After learning that the art thief she has been chasing is her ex-lover, an officer working for Interpol concocts a plan to catch him red-handed.

When a plane crashes at sea, dolphins rescue a little boy and raise him as family. He lives a carefree life beneath the waves until an evil monster seizes power over the underwater world. The boy is banished to dry land, where a kind-hearted captain takes him in. With the captain’s help, the boy sets out on a journey to solve the mystery of his true identity.