"I've now got my head around it, and I feel very honoured and privileged and I'm excited."
Through his time in Rotorua, he said Te Arawa elders had been "very kind" to him.
"I know they have high expectations of me, as I have of myself."
Mr Pewhairangi replaces Bruce Horne, who retired at the end of last year.
The catalyst for joining the police 15 years ago came from his first dealings with police.
As an 11-year-old at home, he spotted a bunch of guys out the window stripping a car.
"Mum wasn't home and I made the conscious decision I was going to ring the police."
The police officer who came thanked him and shook his hand, leaving a mark on the "impressionable kid".
"Whatever he said gave me a real buzz, I felt really special."
He first ventured into teaching - before moving to the police force.
"I joined the police to make a difference, to help people."
Starting in general duties in Lower Hutt he was "hoodwinked" into joining the CIB and trained to be a detective. Because of his teaching background he found he enjoyed identifying talent, and coaching and mentoring that talent.
From there his career has included recruitment roles at the Royal New Zealand Police College, and working as the sergeant in charge of the Petone station before moving to Rotorua four years ago.
He said wife Shelley, also a police officer, was instrumental in the move.
"I was a bit of a home boy, I was quite comfortable in Wellington."
Since being with the police in the Bay of Plenty he has held numerous roles, most recently as the Maori responsiveness manager.
Last year he was appointed to the commander in charge of the Armed Offenders Squad.
He was a member of the squad, although not the leader, during last year's Kawerau siege.
"I'd only just come into the squad and I was just getting used to the routines."
It's an incident which clearly had an impact.
"It was a challenging time for all of the Rotorua police staff.
"Something I learnt throughout that time - particularly the Kawerau siege - was that when the going gets tough, we've got some really courageous people ... who I am really proud of and proud to work with."
He is quick to point out he doesn't just mean those who were on the ground at Kawerau. He's talking about the staff back at the station too, the wider policing family.
"Those were tough times for families, children, grandchildren. If anything it inspired and motivated me more."
On a personal level, Mr Pewhairangi said the move to Rotorua was "just a breath of fresh air".
"We love it here ... the people, the culture. It's an exciting place to live and I feel blessed to be here. The kids are thriving."
With two young boys - Tana turns 5 today, and 6-year-old Whetumatarau - family is important.
The kids are in immersion Maori schooling, and Mr Pewhairangi is the proud coach of the Under 6 Grizzlies team at Marist St Michael's.
"They are great kids. They are our future leaders."
He described himself as "a bit of a liquorice allsort", referring to his sporting background which included representative rugby league, premier rugby, and managing the White Sox softball side at two world championships.
"I really enjoyed my time in the high performance sport environment."
He said it was those he skills transferred into the policing environment. He wants to embed that culture into the team, with an initial focus on getting to know his staff as well as developing relationships with key stakeholders.
"Living and leading the values are critically important. That's the promise we made to Aotearoa New Zealand."
Mr Pewhairangi said a focus would be leading the transition of the police away from just a "command and control environment" to a high trust environment and future-proofing the organisation.
He's a big believer in "the power of a cup of tea" - sitting down with someone and seeing intentions are the same can be as strong as any memorandum of understanding.
"We do have to be bold and brave. I don't have all the ideas."
He plans on being "accessible and approachable".
"People will see me, come and say kia ora."