Japan coach Jamie Joseph was not a happy man following his team's 47-29 victory over South Korea at the weekend at Incheon Namdong Asiad Rugby Field.

The former New Zealand and Japan international said his team, which contained 11 new caps, had been "out-passioned" by the South Koreans and that a number of the more experienced players had "not done the hard work" expected of them.

He will, however, be somewhat pleased to know that the players blamed no one but themselves following the lackluster opener to this year's Asia Rugby Championship tournament.

"I was very honored to make my international debut today. However, we have a lot of things to think about after our performance," said captain and scrumhalf Yutaka Nagare, one of the 11 players making their first appearance for their country.

Vice captain Shintaro Ishihara admitted the team had failed to put into practice what they had been working on in camp.

"Things were pretty tough out there today," the loosehead prop said. "After four weeks together in the National Development Squad environment, we did not really achieve what we set out to do in this first test together. We now have to look ahead and stamp our authority on the upcoming tests."

It was a view backed up by lock Yuya Odo.

"We are still a long way off the goals Jamie has set for us, but our next test is at home and so we want to work hard to improve our game."

Leading 35-12 at the break, Japan would normally have expected to have used their superior fitness to run up the scoreboard in the second half.

But they were up against a resilient host side that actually had the better of the second 40 minutes.

"We fell off the pace late in the game and this is something we have to iron out for the rest of the series," noted flyhalf Jumpei Ogura.

As Joseph pointed out, it was the first run-out for the side so he expected some mistakes with ball in hand.

"You are always going to make mistakes in attack when you play together for the first time and that doesn't bother me," he said. "But defensively we missed a lot of one-on-one tackles and we weren't desperate at times to get back."

Fullback Seiya Ozaki epitomized that.

The young student looked good coming forward but struggled at times in defense.

"Our attack worked reasonably well and we scored some good tries, but our communication in defense and one-on-one tackling still leaves a lot to be desired," he said.