Japan are gearing up for a tough examination of their set-pieces, especially the scrum, when they take on powerful France in their World Cup opener, according to forwards coach Michael Byrne.

Asia's top side have long been noted for the speed and talent displayed by their backs, but have struggled when going up against the big packs sent out by the top sides.

And in Auckland's North Harbour stadium on Saturday, they will be going up against what many see as the best scrum in the world.

"It's going to be a tough day, like most of the teams who played the French we'll have a tough day in the scrum. We had a pre-World Cup camp in Italy and the boys were exposed to an Italy scrum which is also a very, very good scrum," Byrne said.

"We worked hard on understanding how the opposition scrum works and we've been working hard on our mindset around our scrum. When you look at the French and Italian scrums, they pride themselves on the strength part of the game and having a very good scrum.

"We respect that and we've been working on getting our set pieces right. The boys are looking forward to going up against one of the best in the world and we're looking forward to the challenge," he added.

Japanese hopes of standing up to the French were given a knock on Wednesday with the news that New Zealand-born lock Justin Ives would be unavailable for the opener as he has not fully recovered from a knee injury he picked up against Italy.

"Unfortunately, I won't be in the first game. It is unbelievably frustrating. The excitement level in New Zealand for the World Cup has just been unbelievable. I would have loved playing the first game. I'm gutted I'm not involved," he said.

Japan have played in all six editions of the World Cup but have yet to make it out of the group stages after winning just one of the 20 games they have played (against Zimbabwe in 1991).

Realistically their chances in Pool A against France and tournament favourites New Zealand are next to zero, but they will be aiming to win the other two encounters against Tonga and Canada.

"We play the fourth and first-ranked teams in the world and for us it's about being competitive, and Tonga and Canada are the games that are really important for us," head coach John Kirwan said.

Still, the Japanese players believe they can learn a lot from France and the All Blacks as they continue their long-term programme of forging a competitive team to take part in the 2019 World Cup on home soil.

Skipper Takashi Kikutani said it would be a honour for the team to take the field against such giants of the sport.

"In Japan, we don't have often the opportunity to play against tier one teams, we are lucky," he said.

"We will do our best to keep our tempo and game control. We have our game plan, most important is we keep our tempo, move the ball and play."

SAPA-AP