''Mahana'' tells the story of two Maori families, the Mahanas and the Poatas, who are bitter rivals. The family rivalry purportedly dates back to the Tamihana Mahana (Temuera Morrison) falling in love with Ramona (Nancy Brunning) and snatching her away from her betrothed, Rupeni Poata (Jim Moriarty). By the late 1950s, Tamihana Mahana is the patriarch of the Mahana clan and runs a successful sheep shearing family business in the Gisborne District. The headstrong Simeon Mahana (Akuhata Keefe) chafes under his grandfather's authoritarian rule. As punishment for making snide remarks during the family's dinner prayer, Tamihana assigns Simeon household chores. While cleaning his grandmother's study, Simeon discovers a photograph of Ramona Mahana and Rupeni Poata as a couple.