It is winner takes all in Nantes today to determine who plays Wales in the quarter-finals.
Both sides have yet to fire into gear in this tournament with Japan suffering a heavy loss to England in between wins over Chile and Samoa.
Argentina kicked off with a disappointing display against 14-man England before beating Samoa unconvincingly 19-10 and thrashing Chile 59-5 last weekend.
Japan head coach Jamie Joseph has made one change to his starting XV from their 28-22 win over Samoa with Siosaia Fifita replacing Jone Naikabula on the left wing.
Eight of the XV have started every game at RWC 2023: Amato Fakatava, Keita Inagaki, Jiwon Gu, Jack Cornelsen, Michael Leitch, Rikiya Matsuda, Kotato Matsushima, and Ryoto Nakamura.
Kotaro Matsushima, Japan's top try-scorer at the 2019 tournament with five, is the only Brave Blossom to have played every minute but has yet to score a try.
Captain Kazuki Himeno is yet to miss a tackle at the tournament, completing all 31 attempts.
For the Pumas, Gloucester fly-half Santiago Carreras returns in place of Nicolas Sanchez as head coach Michael Cheika makes 11 changes to the side that beat Chile with only Guido Petti, Marcos Kremer, Juan Martin Gonzalez and Lucio Cinti retained.
TEAMS
JAPAN: Lemeki, Matsushima, Riley, Nakamura, Fifita, Matsuda, Saito; Inagaki, Horie, Gu, Cornelsen, Fakatava, Leitch, Labuschagne, Himeno (c) Replacements: Sakate, Millar, Ai Valu, Dearns, Saumaki, Nagare, Yamanaka, Naikabula
ARGENTINA: Mallia, Boffelli, Cinti, Chocobares, M Carreras, S Carreras, Bertranou; Gallo, Montoya (c), Modella, Pagadizabal, Lavanini, Matera, Kremer, Gonzalez Replacements: Creevy, Sclavi, Bello, Alemanno, Rubiolo, Velez, Sanchez, Moroni
Referee: Ben O'Keeffe (NZ)
