Japan face a huge task in their opening World Cup match against France on Saturday but coach John Kirwan wants his players to show courage through adversity.

Japan and New Zealand were wracked by earthquakes this year and Kirwan, an All Black wing great, said Monday he wants his team to play with a commitment to those people still suffering hardship from the disasters.

An earthquake and tsunami in Japan on March 11 left 20,000 dead or missing and triggered a nuclear crisis, less than a month after an earthquake killed 181 people in New Zealand's second largest city of Christchurch.

Kirwan, who is preparing the Japanese team for their seventh World Cup in New Zealand, said his players had dedicated their season to the Japanese people.

"We play for the people who we love and especially at the moment with New Zealand and Japan with the earthquakes, it's very important that we take those people with us," Kirwan told reporters at team training.

"It's a very important time for us to go on to the field and show that emotion."

Kirwan said he did not want to use the tragedy to primarily motivate his players as it was in "bad taste".

"One of the things that I don't need to do is use the tragedy as a motivation because I'm not prepared to do that because for me that is bad taste," he said.

"I will leave each player to deal with how they want to use it.

"I want to send the message of courage and commitment back to the people.

"The scoreboard is not important, but our attitude is right through the tournament."

Kirwan has the utmost respect for what the people in Japan and Christchurch have gone through since the disasters.

"The greatest thing the people of New Zealand and Japan have shown is courage through adversity," he said.

"I think that is a very important message, not only for our rugby team, but for everyone.

"That having respect for the person next to you and showing courage through hard times is certainly how I want to live and certainly how the team want to play."

Since the last World Cup in 2007, Japan have won all four editions of the Asian Five Nations and are yet to lose a game. In July, they secured their first-ever Pacific Nations Cup title with a dramatic victory over Fiji.

The performances have boosted optimism that Japan, who will host Asia's first World Cup in 2019, can add to their sole win in this month's tournament after their 52-8 success against lowly Zimbabwe in 1991.

Japan are ranked 13 but France, who finished second behind England in this year's Six Nations, are the highest-ranked European nation at four.

AFP