Ireland were unable to repeat their 2018 Grand Slam heroics, finishing third after losing to both England and a Wales side that pulled off a clean sweep to secure the title in March.
Captain Best says Ireland will be ready to put that disappointment behind them at the showpiece in Japan.
Best, who will retire after a tournament, which will also bring an end to head coach Joe Schmidt's reign, said: "When Joe first came in the big question was 'how do we perceive ourselves?'. The big answer was 'inconsistent'.
