Johnston describes dealing with issues of land, commerce, culture, and human rights as her "dream job". She has always been passionate about social justice and equality, volunteering in women's refuges and in community law.
"I have an affinity for people and issues that make people vulnerable, particularly women. Maybe it relates to being brought up without a Dad," she says.
Her CEO appointment - replacing Keith Palmer, who left three years ago but who remains a consultant - follows a year-long review of Wakatu's infrastructure and capability requirements. She has been its first general counsel for the past four years and now combines the two roles.
Johnston has spent "hundreds and hundreds of hours" overseeing ground-breaking legal action in which Wakatu asked the courts to recognise that the Crown breached its trustee and fiduciary duties to the area's original Maori landowners. It is using legal remedies, rather than political and negotiated ones under the Treaty of Waitangi Act, to argue that when the Crown granted land to the New Zealand Company for its Nelson settlement, it inherited the company's promise to set aside a tenth of the area as reserves for Maori.
Wakatu Incorporation was set up in 1977 to administer the remaining Nelson Tenths land.
The complex case was heard in the Supreme Court in October 2015, but a decision is still pending. A typically cautious lawyer, Johnston carefully avoids any criticism of the court for what she says is an "unusual" delay.
Taulelei has been friends with Johnston since studying law at Victoria University 20 years ago, and says she "leads with the utmost humility and embodies so many of the attributes of strong Maori women in history".
Johnston is keeping a close eye on the Government's Te Ture Whenua bill, which aims to reform the law relating to Maori land. She criticises the legislation as lacking clarity and is concerned that it could create problems for Maori incorporations. You get the feeling nothing will slip by Wakatu on her watch.
Johnston and her younger brother were raised in the Bay of Plenty, mainly Rotorua, by her Scottish mother and grandmother - both "strong women", she says. Her father is Maori and her whakapapa Ngati Tama, Ngaruahine and Ngati Whawhakia.
She always wanted to be a lawyer and specialised in international law, exploring indigenous people's rights and environmental law.
Her extensive legal experience includes clerking at the Court of Appeal, working on Treaty claims in private practice, working as in-house counsel for the City of Westminster, the UK's largest local authority, while on her OE, teaching law and doing research at the University of Auckland, and setting up a private practice in Rotorua specialising in Maori issues.
Mentors include Maori Land Court judge Caren Fox, Rotorua lawyer and activist Annette Sykes, and retired Court of Appeal judge Ted Thomas. "People with critical voices are important to help illustrate things that are not quite right about society," she says.
She also spent time working with the United Nations Permanent Forum on Indigenous Issues, where indigenous groups were interested in Maori rights as an example of what they could do. "While it's difficult to compare the way we have been treated from others, there are some common themes across the world such as loss of land, culture and resources. The policy and legislative responses have been quite different in different jurisdictions," she says.
Johnston and her family - husband Lane Hawkins and children Daisy, 11, and Mahuru, 7 - shifted to the top of the South from the Bay of Plenty when she became general counsel at Wakatu.
Next year, the incorporation turns 40. Johnston says work has already been done on the next 40 years, in an inter-generational plan with a 500-year span. Called Te Pae Tawhiti, the plan is for the wellbeing and prosperity of its people, which Johnston says "begins every day."
Director Miriana Stephens is overseeing an innovation strategy that should bear fruit in a couple of years, including improving land use and sustainability, high value nutrition and food ingredients, low alcohol wine, improved processing and production methods, and use of waste.
Johnston says the owners she lives among will tell her when they're unhappy.
"I'll be in the supermarket and they'll come over and raise any issue," she says laughing. "Quite often around the board table we'd ask 'what would our owners think of this?' and that question helped most of us immediately know the answer".
Kono had a record year this year and Wakatu's profits more than doubled to $11m but its core purpose is not to make money, Johnston says. "That's essential to do what the actual purpose is - to look after our families and their place in the world."
Kerensa Johnston
• Age: 41
• Role: CEO, Wakatu Incorporation
• Grew up: Bay of Plenty
• Career includes: private practice, in-house counsel for City of Westminster, teaching law and research at University of Auckland
• Married with two children
