Expect 'most competitive World Cup ever', says Japan-based Kiwi coach Robbie Deans

Make no mistake, Japan 2019 will be the most competitive Rugby World Cup to date. That's according to former Crusaders and Wallabies coach, Kiwi Robbie Deans.

Now calling Japan home as the head coach of Top League side Panasonic Wild Knights, 60-year-old Deans has been based three hours outside of central Tokyo for the past five years.

"We didn't really have a set idea of how long we'd stay but we just enjoy it, we enjoy the place," Deans told 1 NEWS.

"We enjoy the people. We love the food and there's great balance, you know. We get to get home."

Kiwis have become hot property in Japan's Top League, already boasting former Highlanders and Otago prop Craig Millar at the Wild Knights, while current All Blacks Sam Whitelock and Matt Todd will arrive after the World Cup.

Assistant coach and former Japan international Tomokazu Soma explained just why New Zealand talent is in such high demand - on and off the field.

"They show us great examples so we chase them, play them, work together then get better."

As for this World Cup, expect conditions to play a huge part in the All Blacks' quest for a third straight World Cup, warns Deans - sweltering heat having met the side after their arrival earlier this week.

"They'll struggle, as you've just experienced.

"People talk about heat and you think, 'Yeah, yeah, I've experienced hot'.

"But then you experience heat here in July, August, September and it's different. It's humid heat."

That heat has seen the All Blacks go for a more mobile look to their 31-man squad. However, Deans points out that they're not the only ones following that gameplan.

"They've clearly hung their hat on attack and that's New Zealand. But they're not alone now in that.

"It's gonna be the most competitive World Cup ever."