All Black boost for Sunwolves coaching ranks
Mauger will coach the backs and Tiatia the forwards under head coach Mark Hammett, another All Black.
The Sunwolves appear to be several weeks behind other sides in their preparations.
Most teams began pre-season training with a full complement of coaching staff well before Christmas.
"The key focus in the initial stages is to put systems and structures in place with our Sunwolves players and help get them up to speed," Mauger said before departing for Japan on Tuesday.
Mauger played two tour games, but no Tests, for the All Blacks in 2001 and is a brother of 45-Test centre and now Leicester Tigers head coach Aaron Mauger.
"This is an exciting stepping stone for me in my coaching career," Nathan Mauger said.
"I think the expansion of the competition starting next month will be good for the new teams and countries. I look forward to being part of the build towards the 2019 Rugby World Cup in Japan."
Tiatia, who played Tests against Tonga and Italy in 2000, announced his involvement with the Sunwolves via a Facebook resignation from his post at a Wellington school.
"It is with a heavy heart that I would like to inform you all that I will be leaving as the director of rugby here at Scots College," Tiatia wrote.
"I have recently accepted a role in the new Japanese Super 18 franchise as the forwards coach in this year's inaugural Super 18 competition.
"The timing is obviously not fantastic and I want to apologise for that but I am a great believer that 'nothing happens by accident and it happens for a purpose'."
The Sunwolves join an expanded 18-team Super competition this year with their first game against South Africa's Golden Lions on February 27.
Agence France-Presse
