Hema is a figure in both Hawaiian and Maori mythology.
In Māori mythology, Hema is a son of Whaitiri and Kaitangata and the father of Tāwhaki and Karihi. In North Island stories, he was killed by the Ponaturi, evil creatures who live by day in the water. Tāwhaki, Karihi and their mother trick the Ponaturi into entering a house, and then locked them in, claiming there was still time before the dawn. They then opened the door after sunrise, and the Ponaturi were killed by the exposure to sunlight (Tregear 1891:61, 496). The only survivor (in one account) was Tonga-Hiti and in another account kanae, the grey mullet.
In Hawaiian mythology, Hema and his brother Puna are sons of Aikanaka by Hinahanaiakamalama, according to the Ulu genealogy. His son was Kaha'i. Hina is disgusted by her children's dirtiness, and she goes to the moon. In some accounts, Hema sails to a far-off country, where he is killed by a people which habitually kills all strangers. Kaha'i goes on a journey to find him. Other accounts have Hema as a son of Mahina.