Rewritten version of Yoku Shioya as Triton's story:
Triton was taken in by a human boy named Kazuya when he was just a baby, and grew up on land, learning about human society. However, despite his new life, Triton couldn't forget the tragedy that had befallen his family - all the mermen and mermaids of his kin were killed by the Poseidon family. Driven by revenge, Triton left Kazuya behind and returned to the sea with his dolphin friends Ruka, Uru, Karu, and Fin. Together, they embarked on a one-man war against the Poseidon family.
On their journey, Triton met Pipiko, the last surviving mermaid. With her help, he was able to stop Poseidon and his evil minions, and seek vengeance for his family. Through it all, Triton remained determined and focused on his mission, using his skills as a merman to great effect in his quest for justice.