Kaha'i
Kaha'i (specifically: Hawaii; elsewhere Tafaki, Tafa'i, Tahaki, Tava'i, Tāwhaki) is a handsome Polynesian demigod whose exploits were popular in many Polynesian mythologies.
Hawaii
In Hawaiian mythology, according to Tregear, the legends about Kaha’i are 'extremely fragmentary and vague', but they indicate that Hema traveled to 'Kahiki' (perhaps Tahiti, but more probably to kahiki 'the distance', as kahiki can be understood to include all of the islands in the Pacific Ocean) to receive a tribute called palala for the birth of his son Kaha’i. There he was captured by the Aiaia (a bird, messenger of the god Kane), died, and was buried in Ulu-paupau. Kaha’i decided to go and avenge his father. A rainbow was the path over which he and his brother ‘Alihi ascended into the skies, where they asked Kane and Kanaloa where Hema's remains were to be found.
E.R. Tregear, Maori-Polynesian Comparative Dictionary, (Lyon and Blair: Lambton Quay 1891), 497.
Tuamotus
In the Tuamotuan version of the myth, Tahaki and Karihi are twins, but only Tahaki has magical powers. Tahaki's father, Hema, trespassed on lands belonging to the goblins of Matuauru in order to go crabbing. They captured him and took him prisoner, and Tahaki and Karihi begin a quest to rescue him. En route, Karihi accidentally gets snared on the fishing line of their blind grandmother, Kuhi. Tahaki throws coconuts at the old woman and when they hit her, her sight is miraculously restored. Tahaki again sets out to save his father, whom he finds in a pit on Matuaru and rescues. He then proceeds to Hiva-nui, the land of the goblins, with a strong net called Tukutuhuraho-nui (great spider). Ensnaring the goblins, he beats them to death. While returning home via the land of the fish, he gives his dark skin to the Hami-kere fish. After his death, Tahaki goes to the sacred sky of Tane, where it is set apart to rule over Havaiki-nui.