Head coach Jamie Joseph said Thursday that Japan had "turned the page" ahead of their final Rugby World Cup tune-up against Italy after a spate of red cards and injuries.
Joseph welcomed back Michael Leitch to the starting line-up to face the Italians in Treviso on Saturday after the former captain served a two-match ban for being sent off against Samoa last month.
Loose forward Pieter Labuschagne is still suspended after his red card in the seventh minute of Japan's 35-12 loss to Fiji in Tokyo two weeks later.
Joseph said the dismissals had put "a different spin on players' confidence" but he backed them to turn it around against the Italians.
"I think we've had all of our bad luck – it's all over, finished now," the New Zealand-born coach said.
"We've got some good luck coming. In terms of the condition of the team, physically we're in really good nick.
"We've just got to start playing rugby now."
Japan kick off their World Cup campaign against Chile in Toulouse on September 10 and will also face England, Argentina and Samoa in Pool D.
The 2019 World Cup quarterfinalists have had mixed results in recent weeks, beating Tonga but losing to both Samoa and Fiji at home.
Joseph said the players' "anxiety" as they sweated on their World Cup places had been an issue but he backed them to play with freedom now that he has named his squad.
"Mentally, we've turned the page," he said.
"I think selection for the World Cup is important for the players to be able to just really focus on playing."
Joseph brought flanker Shota Fukui, who has only one cap to his name, into the starting line-up and named uncapped lock Amanaki Saumaki among the substitutes.
Italy go into the game off the back of a 57-7 home win over Romania last week, following away defeats to Scotland and Ireland.
Joseph said the Italians, who will face New Zealand, France, Uruguay and Namibia in World Cup Pool A, were the "perfect" opponents for Japan's final tune-up.
"We're going to play a team that is experienced and hard in its play and I think that's the kind of test match that we need leading into the World Cup," he said.
Italy (15-1):
Tommaso Allan; Ange Capuozzo, Juan Ignacio Brex, Luca Morisi, Montanna Ioane; Paolo Garbisi, Stephen Varney; Lorenzo Cannone, Michele Lamaro, Sebastian Negri; Federico Ruzza, Niccolo Cannone; Simone Ferrari, Giacomo Nicotera, Ivan Nemer
Replacements: Luca Bigi, Danilo Fischetti, Pietro Ceccarelli, Dino Lamb, Giovanni Pettinelli, Manuel Zuliani, Martin Page-Relo, Paolo Odogwu
Japan (15-1):
Kotaro Matsushima; Semisi Masirewa, Dylan Riley, Tomoki Osada, Jone Naikabula; Seungshin Lee, Yutaka Nagare; Kazuki Himeno, Shota Fukui, Michael Leitch; Uwe Helu, Jack Cornelsen; Jiwon Gu, Shota Horie, Craig Millar
Replacements: Atsushi Sakate, Keita Inagaki, Asaeli Ai Valu, Amanaki Saumaki, Ben Gunter, Naoto Saito, Rikiya Matsuda, Ryoto Nakamura