Ben Herring, who joined the Highlanders last year as a resource coach and is also the Otago assistant coach, is joining the Sunwolves and the Japanese national team for the next three years.
He will link up with former Highlanders coach Jamie Joseph as the new Japanese set-up fills with former Highlanders personnel.
Joseph, who is the head coach of Japan until the next World Cup, will be joined by Tony Brown as the attack coach for the national side after the Super rugby season finishes next year while Herring will join the side as the defence coach.
Simon Jones, who has worked with the Highlanders and other southern sporting teams, has joined the outfit as the head strength and conditioning coach.
Highlanders assistant coach Scott McLeod turned down a role with Japan but that option has been picked up by Herring.
Herring (36), who only arrived back in New Zealand last year after a career playing and coaching overseas, said it had taken a long time to decide.
Joseph had been in touch mid-year and was a hard man to say no to, Herring said.
''It wasn't really in the plan but we thought about it a lot and then have only just decided to say yes. We really enjoyed our time over there and it is a nice place to live and work,'' he said.
''Being a pro rugby coach you've got to take the opportunity to learn and grow and sometimes you have to travel to do that.
''Long term we want to come back here at some point and I want to keep getting more experience at this level. I want to be a head coach so this sort of experience is really going to help.''
Herring is originally from Auckland and came south to attend the University of Otago. He played for Otago and Southland and then the Highlanders and Hurricanes.
A rangy openside flanker, he left to play for Leicester in the English Premiership but a couple of nasty concussions forced him into retirement before he celebrated his 30th birthday.
He went straight into coaching and has coached in England, Japan and Canada before he moved back to New Zealand last year.
He was involved in the Canadian national set-up and coached the NEC team in Japan with former Highlanders coach Greg Cooper.
Herring said joining the Sunwolves, the Super rugby side, would be a new experience. The head coach of the Sunwolves is former All Black Filo Tiatia.
''It is going to be different. Almost starting from scratch with them. It is a massive transition for them at the moment. Just the structures of how they even do things.''
Herring said he was not a huge fan of the travel which the Sunwolves had to carry out but that was just part of the job.
He and wife Wal have three children - Huxley (7), Rocket (5), Eckhart (2) and the family would be based in Tokyo.
He has unfinished business with Otago heading into the business end of the Mitre 10 Cup as the side eyes up a win of the Championship division.
He will also have to relinquish his position as head coach of the Alhambra-Union premier side.
''That is going to be real tough. They're just the best club in the world. I just loved it. If I could I'd be back there in a second. They're such a great bunch of guys.''
Highlanders winger Ryan Tongia has joined French club Bayonne as medical cover. He played the past two seasons for the Highlanders but had limited action and was not re-signed for the 2017 season.