A boy was led by a fairy to a mysterious ocean world called Bariland and goes missing. His best friends Mocha and Paripariume set out to search for him. They are captured by pirates and Mocha nearly ends up drowning, but is saved by the beautiful mermaid Koucha. Years pass and the fish-hats plot to take over the world. Can Mocha and his friends find the boy and stop the bad guys?