Nepia was born in Wairoa in Hawkes Bay. While his birth certificate stated that Nepia was born in 1905, he later claimed to have been born in 1908. After finishing primary school in Nuhaka, Nepia was to attend Te Aute College but went to the nearby Maori Agricultural College instead. In 1926, Nepia married Huinga Kohere. They had four children, three sons and a daughter. Nepia and his family settled on a dairy farm on the East Coast.
Nepia was selected for the Hawkes Bay provincial rugby team in 1922. At that time Hawkes Bay had one of the strongest teams in New Zealand and held the Ranfurly Shield. Nepia initially played on the wing but was later shifted to second-five eighth. In 1924 Nepia was selected as a full-back for the All Blacks tour to the United Kingdom. Nepia was one of the stars of the tour. He played in all 32 games – being the only player to do so, and scored 77 points. As the team did not lose any matches, they came to be known as The Invincibles. Nepia was a fine full-back, with a safe pair of hands, a strong kicking game and a fierce tackle. Before games on the tour, he led the team's performance of a haka which had been composed for the tour. Nepia was omitted from the 1928 All Blacks tour of South Africa, probably on racial grounds. Nepia returned to the All Blacks for tours to Australia in 1929 and against the British Lions in New Zealand in 1930. These were his last games for the All Blacks. In 1935 Nepia went to England to play rugby league professionally being signed initially by Streatham and Mitcham Rugby League Club in London for £500. His family remained in New Zealand. Because rugby union was a strictly amateur game at the time, Nepia was cast out from rugby union. Nepia later transferred to Halifax. In 1937 he returned to New Zealand and played league for Manukau and played for the New Zealand Māori and New Zealand rugby league team. During July and August 1937 Nepia traveled to the South Island, representing both Hornby and Canterbury. In 1947 the New Zealand rugby union held an amnesty allowing former league players to return to rugby union. Nepia played a first-class match in 1950 against a Poverty Bay side captained by his eldest son. This made Nepia the oldest New Zealander to play in a first-class game, and was the only time a father has played against his son in a first-class game.
Later life
Following his retirement from playing rugby Nepia became a referee and worked as a farm manager in the Wairoa district. In 1975 his wife Huinga died. Nepia lived out his final years with his son Winston in Rangitukia. He died in 1986.
