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. Banished to dry land, the boy is taken in by a kind-hearted captain. With his new companion's help, the boy embarks on a journey to solve the mystery of his true identity.
| Actor | Role |
|---|---|
| PPolina AvdeenkoDolphin Boy (voice) | Dolphin Boy (voice) |
 Yuliya RudinaDolphin Snezhok / Captain’s wife / Flounder 1 (voice) | Dolphin Snezhok / Captain’s wife / Flounder 1 (voice) |
| AAlexander FeninCaptain (voice) | Captain (voice) |
 Boris KhasanovOctopus / Shark (voice) | Octopus / Shark (voice) |
 Alexander VasilyevTurtle / Blue fish / Flying fish / Seahorse / Dolphin / Old sailor (voice) | Turtle / Blue fish / Flying fish / Seahorse / Dolphin / Old sailor (voice) |
 Julia ZorkinaWitch / Girl’s mother (voice) | Witch / Girl’s mother (voice) |
 Vasilisa UshakovaNana / Fish / Flounder 2 (voice) | Nana / Fish / Flounder 2 (voice) |