He'll have the weight of the host nation's expectations on his shoulders and it's a challenge he's not shying away from.
But who is the man of Ngati Maniapoto and Ngati Rarua descent?
Joseph has sport in his blood.
"Very sporting family, both parents played sport and coached sport. Summer's were full of softball, Mum played hockey in the winter. Dad played rugby and softball."
The whole whanau were talented athletes.
Joseph's grandad and great grandfather played for New Zealand Maori, other relatives played for the All Blacks.
His great uncle John Hoani MacDonald, known as Jack, played top level rugby too, as well as rowing at the 1932 Olympics, becoming one of the first two Maori Olympians.
"We'll be competing, before dinner and after dinner. My uncles played for the All Blacks, the Maori All Blacks, cousins have played for the All Blacks, so we were a really sports orientated family. We got brought up in a really competitive house."
But it was his dad, a Marlborough prop who also played for the Maori, who was Joseph's idol.
"My father would have been my biggest influence, because he was an ex-rugby player and an ex-rugby coach, who played at the highest level for a number of years."
But as Joseph grew and changed as a rugby player, so did his influences.
"When you're a young player coming through New Zealand, that becomes your coach. I've had some very good coaches. I've had John Hart, Laurie Mains, Gordon Hunter and Tony Gilbert , so I've had four All Black coaches in my rugby career, which is pretty unique."
Those influences eventually leading him from playing to coaching, first with Wellington, the Hurricanes and Highlanders, then from the land of the long white cloud to the land of the rising sun.
Having lived in Japan for 10 years, first as a player now as coach of the national team, Joseph says anything less than a quarter-final appearance will be considered a failure for this year's World Cup hosts.
"I've been employed to come over here for a home World Cup and it's very clear what their (Japan Rugby Union) ambitions are and what they wanted (taking Japan to the knockout stage for the first time). It's a big challenge, but I just can't wait to get there."
and if Japan were to make the knockout rounds for the first time, they would likely face the All Blacks.
A prospect that has Joseph salivating.
"Oh 100 percent, yeah, crickey! First of all it's never been done (Japan advancing from pool play) and it's a difficult road. But that's why we're here and yeah, if we could crack that, it would be wonderful."
It would also add another wonderful chapter to Joseph's already storied career.