Warren Gatland wants Wales to "send out a message" against England today that would show they mean business at the World Cup.
The countries face a quick-fire Millennium Stadium rematch after England won narrowly at Twickenham last weekend, and Gatland is only contemplating one outcome.
"We have spoken as a group about how important it is for us to win," said the Wales coach, who has called up James Hook, Gavin Henson, Lloyd Burns and Luke Charteris for their first pre-tournament starts.
"If we are going to be serious contenders in this World Cup, we need to send out a message that we are good enough to beat England at home and do that next week as well [against Argentina]."
Declan Kidney is delighted Ireland will test themselves against one of the World Cup's heavyweights when they face France today. "We've been concentrating 99 per cent on ourselves going into this game, but we know France will be a powerhouse at the World Cup," he said.
"Because of that they will be a good test for us. It will be interesting to see how we get on.
"In France, they could pick three or four teams of similar quality. That's the strength of French rugby."
John Kirwan, the Japan coach, said he has brought his team to Europe to help in their long-term development with future World Cups in mind.
Japan face Italy today. Next week they return to Tokyo to face the United States before heading off to New Zealand for the World Cup. "We have short-term goals and long-term goals. The long-term goal is to make the top eight in [the World Cup in] 2015 and then make our own final in 2019 [when the tournament will be held in Japan]," Kirwan said.