Piwai Toi was born at Kokohuia in the Hokianga and was educated at Omapere Primary School. He worked as a railway journeyman, a gum digger and as a dairy farmer on a small holding in the Māori (ancestral) community of Kokohuia. He married Kare Te Aroha nee Leaf in 1934 and raised six children and two other relatives. Toi’s son, Archdeacon Wiritai Toi, writes of his father: "Dad was a humble person, the potiki of his family whose parents both died when he was very young. He was raised by uncles and aunts in the South Hokianga, and left school at 14 years of age. He became an authority on Hokianga, its history and environment." Archdeacon Toi adds: "My father was a founding member of Te Whakarongotai a Toi Marae, which stands on tupuna land at Kokohuia, overlooking the entrance to the beautiful Hokianga Harbour. He was the Secretary to the Kokohuia Komiti Marae, and the minutes of their meetings go back to 1929. However, the Marae itself was not erected until the late 1950s. The last entry Dad made in the Komiti Marae minutes was in May 1976. He died in June of that year, aged 72 years. Dad served on the local Parish Council and was the Parish representative for many years at the General Synod of the Anglican Church. He was also involved with all local Māori Committees, he founded the local Youth Club, and became well-known as a kaumatua for Marae throughout South Hokianga. Dad did not go to serve in the 2nd World War; he was considered too old, but he took an active part in the Home Guard. At the time of Opo the dolphin, Dad was very much sought after by television people to talk on Māori perspectives of the Opo phenomenon. He was interviewed by James McNeish and by Keith Bracey. Both of my parents also had movie parts in the film, Runaway with Kiri Te Kanawa in the 1960s."
- Correspondence from Archdeacon Wiritai Toi: 28 Feb. and 12 Mar. 1998, and 26 Oct. 2004.
- "Opo The Gay Dolphin". Te Ao Hou 23 (1958): 22-24. Excerpt rpt. in Mana: The Māori Magazine for Everyone 100 (2011): 94-95.
- Toi writes of his encounters with Opo the dolphin which lived in the Hokianga River between 1955 and early 1956. Described by Māori elder Hohepa Heperi as "the fish of peace, a legacy from Kupe’, Opo drew hundreds to Opononi every weekend until her death on the rocks in March 1956.
- "He Reo No Te Ao Tawhito." Te Ao Hou 24 (1958): 22-23.
- Te Ao Hou prefaces this article with the note that it is ‘the life of a sanitary inspector in bygone days described by his son.’
- "Te Takuate A Kawiti." Te Ao Hou 29 (1959): 58.
- Toi writes a response to a request in Te Ao Hou 26 for information on the location of Te Toka o Mapuna in Hokianga Harbour.