Both Japan and Ireland sit on five points apiece, alongside Samoa, having beaten Russia and Scotland respectively in their opening Rugby World Cup matches last week.
The Irish were dominant in their opener as Joe Schmidt’s side look to answer their critics following a questionable build-up, including a mediocre Six Nations campaign.
The Brave Blossoms are seeking a major upset similar to the one they managed four years ago against South Africa.
They secured a bonus-point win over Russia and from that have surprisingly opted to drop captain Michael Leitch from their starting XV, with Amanaki Mafi coming back into the back row after returning to full fitness.
Ireland are without Johnny Sexton, who picked up a thigh problem against Scotland, while Rob Kearney and Keith Earls are restored to the back three in favour of Jordan Larmour and Andrew Conway.
Robbie Henshaw misses out again with the centre having sustained a hamstring injury earlier this month.
Japan coach Jamie Joseph is confident that benching Leitch will not prove a mistake.
“What I believe around the game, in terms of our bench, we’ve got to have an impact,” he said. “If we’re going to be in a position to win the match, it’s going to come down to the last five or 10 minutes
“And we’ll need clear leadership. Michael has had an injury all year, he’s only played four or five games, and he’s a very key player. We have in-form players playing really well and experienced players coming on. So as a coach I get to have both things.
“Lappies [Pieter Labuschagne] doesn’t speak Japanese, he speaks English, but so does the referee. His leadership is natural, his work around the game is outstanding. I
“’ve been impressed with him as a leader in the last two years at the Sunwolves and he is respected by the players, which is key.”
Squads
Ireland starting XV: Kearney; Earls, Ringrose, Farrell, Stockdale; Carty, Murray; Healy, Best, Furlong, Henderson, James Ryan; O’Mahony, van der Flier, Stander.
Replacements: Cronin, Kilcoyne, Porter, Beirne, Ruddock, McGrath, Carbery, Larmour.
Japan starting XV: Yamanaka; Matsushima, Lafaele, Nakamura, Tupou; Tamura, Nagare; Inagaki, Horie, Koo, Thompson, Moore; Himeno, Labuschagne, Mafi.
Replacements: Sakate, Nakajima, Ai Valu, van der Walt, Tanaka, Matsua, Lava Lemeki.