Japan are only one place below Scotland in the world rankings, but are arguably in better form.
The age-old saying that "you can only play what's in front of you" is particularly apt this week.
On paper, Ireland should have more than enough ammo in their arsenal to outmaneuver Japan and put one foot into a quarter final against South Africa. But it's rarely ever that simple is it?
Japan are at home, something which their supporters will be keen to remind them (and their opposition) of. As they showed in that famous victory against South Africa just four years ago, they are more than capable of performing at the highest level.
Apart from a few results against New Zealand, you'd be hard set to find a time where the Springboks have lost after scoring 30+ points. Without going as far as saying that Japan are very likely to put up a serious challenge against Ireland, it's important to note that we shouldn't be just taking it as a given.
Not that Joe Schmidt and co. ever would take a World Cup result as a given. In 29ºC heat most of the 52,000 fans in the crowd cheering on the Brave Blossoms, anything can happen.
Yeah, we mean anything
That is pretty much Japan's biggest threat: unpredictability. If Scotland are a team that can create a spark from nothing but failed to do so, the possibility of Japan putting up more of a fight remains a possibility.
Even with talisman Michael Leitch being kept on the bench, they're more than capable of pulling something out of the bag. While you'd expect the strong pack Ireland are putting out to win the physical battle, if the game opens up for the likes of last week's hat-trick hero Kotaro Matsushima you'd imagine them pushing the Irish defence to its limits.
Only twice in the past two years have Japan failed to score 20 points or more. This is a run of form that includes games against France, Australia, Italy, and a thrilling 31-60 loss to the All Blacks.
While the results haven't come their way at a consistent level, the foundation is there and the threat is most certainly real. It would be remiss not to mention how familiar this squad is with each other as well.
Skillful, fast-paced and creative. Basically the last thing you want to be facing in that kind of heat six days after a massive shift against Scotland.
They like to throw the ball out wide, with Will Tupuo and the aforementioned Matsushima likely to pose a threat. This is where the experience of Kearney, Earls and Stockdale is going to be of huge importance, as rest assured that scrumhalf Yutaka Nagare will be looking to test them.
While we reckon Ireland's experienced XV and strong bench will be too much for Japan, this one could be a lot closer on the scoreboard than last week.
