"That was a big surprise because everyone expected that Heeni was going to become queen," he said.
"Heeni said she was told by her mother that Tuheitia was to be the king, and when the meetings were happening with the leaders of the iwi she passed that on saying, 'They were the dying wishes of my mother.'"
Pihama said Heeni had been groomed for the job, often travelling with her mother to events, while Tuheitia worked in Huntly as a truck driver, meatworker and at one stage helping to build the Huntly power station.
"He was a simple man, he was a truck driver," Pihama said.
As he was being installed as king after his mother's death, he told Pihama: "I was thinking, 'What am I doing here?'"
Pihama was given unprecedented access to Tuheitia and his family, including his second son Korotangi.
He was arrested as an 18-year-old in 2013, with three friends, for stealing three surfboards and other items near Gisborne. Korotangi was initially discharged without conviction but was later convicted for drink-driving.
"That was the most sensitive topic to speak about. They all spoke about it - the mother and father, the siblings and Korotangi himself," Pihama said.
Tuheitia's wife Atawhai told Pihama that Korotangi was "the king's heart".
Korotangi, now a bricklayer in Huntly, said: "I'm probably just the naughty one, get up to mischief."
In contrast his older brother Whatumoana has often deputised for his father when the king has been too ill to attend events since developing diabetes in recent years. The brothers have a younger sister, Ngawai, who is a kapa haka leader and university student.
