Tome stands behind the bar in Ryokan Mugen and tells me she does not really "get" rugby. Pointing out the massive size of so many players, she half sighs and half giggles. "It makes me think that we Japanese people have different DNA. We are not built for rugby."
Eager to prove her wrong on both counts, out comes the iPhone and I begin googling a few choice videos. Shane Williams scores against South Africa in 2008. Twice. Peter Stringer crosses the line for Munster in the 2006 Heineken Cup Final. Even Jason Robinson burning up the pitch for England.
"Oh, they're so small!" says Tome at first, then her face lights up. "Ha ha! Nobody touches them!"
They say that a good big 'un will always beat a good little 'un, but the history of rugby has continually thrown that logic out the window.
During this tournament, Japanese rugby will be seeking to reaffirm the ideal of a game for all shapes and sizes - an attacking game, a running game. Ireland will need to be on their guard for Japanese speed and flair.
But as travelling rugby fans, we feel a duty to show off the virtues of the game as well. (Not long afterwards, a near 7ft former international lock wanders into the bar, threatening to blow my theory out of the water, but I tried...)
Japanese people are also huge exponents of samurai ideals or bushido - such as courage, honour and loyalty - all aspects that are central in rugby. At least, when it's played in proper spirit. The Irish team's bow to the east stand at the end of last Sunday's match in Yokohama would normally just have been a nice touch for the travelling fans, but here in Japan, it was a PR master stroke, showing respect and humility even in victory.
How incredible it would be to see that now repeated all the way to the final.
This Rugby World Cup has become a massive cultural exchange trip as Irish supporters relish breaking out of the familiar cycle of Cardiff, Paris, London, Edinburgh, Rome.
In turn, Japanese people are living up to their reputation and duly repaying the faith put in their country in organising this tournament. Never have I felt so welcome, so respected and so safe when far away from home. The stewards lining up to high-five supporters as they left Yokohama Stadium last weekend was just one standout in a week of little moments that have made us all smile.
Irish fans heading out for the later stages of the tournament are in for a treat as they will discover the small things that make life easier here. Buses running absolutely on time, to the minute. Trains that travel up to 320kmph. Beer hawkers looking for thirsty punters in the stands. Cup holders in the stadium seats. Orderly queues for the bathrooms.
The only blip is the constant chat that Japan is going to run out of beer, which seems to be a scurrilous rumour based on the small local bars that underestimate the thirst of rugby fans from around the globe.
When you visit here, you will learn the true value of the Japan Rail cards, local sushi joints and cheap takeout beer from Family Mart (you will also learn the true value of an apple is €3. Fresh fruit is extortionate).
Tokyo is a bustling metropolis unlike any other and fans are like flotsam bobbing on the tide of 38 million people - coming together, dispersing and moving on.
Never does the city feel overwhelmed by the occasion - of course, it is too big for that. But except during rush hour on the subway, it rarely feels overwhelming either. Of course, the architecture is capable of making the biggest rugby forward look insignificant.
Its monorails and motorways in the sky are a scene from Blade Runner made real. But there is a calmness to the people, an orderliness that you would never find in London, New York or even Dublin.
The whole tournament does have shades of feeling like a warm-up for the Tokyo Olympics next year.
Already the merchandise is being churned out for the 2020 event, which is Japan's chance to showcase its modernity to the world and prove it has emerged from long and damaging recession. Meanwhile, the rugby merch is limited to a few specific stores and stands.
An enterprising type with a few green T-shirts and scarves could probably recoup the cost of their flights, accommodation and more if they managed to get on the ground here.
But in Japan, souvenirs just don't seem to exist. Despite rugby's more limited appeal, the smaller cities have truly embraced the occasion so far (15,000 Japanese people singing the Welsh national anthem, anyone?)
Getting out of Tokyo is key, at some stage. This is a nation of temples and towers, jungles and mountains, vast factories and tiny shrines.
Irish fans will see more of real Japan today and, going forward, through fixtures against Samoa and Russia in Kobe. That should be a special week, in a smaller city of 'just' 1.5 million people. Beers will be drunk, beef consumed and lifelong friendships made.
Because despite what some Japanese people might fear, we do all have the same DNA. The ideals of bushido can resonate with all of us. And we can all appreciate a damn good game of rugby.
The Left Wing
Luke Fitzgerald has no doubt that Ireland’s forwards can give Jack Carty the platform to slot in seamlessly after Joe Schmidt confirmed that the Connacht out-half will replace Johnny Sexton for Saturday's clash with Japan.
The opening game of the Rugby World Cup between Russia and hosts Japan is hardly the kind of fixture that sets the pulse racing. It's an unavoidable side effect of the nature of international rugby that all World Cups are beset in their early stages by lots of these dead rubbers.