Image copyright Getty Images Image caption The Rugby World Cup will be held in Asia for the first time

The giants of rugby union are preparing to sprint and scrummage their way through a new kind of Rugby World Cup: the Japanese variety.

It's the first time the oval-balled extravaganza has been held in Asia, and with the opening match scheduled for 20 September, visitors are already enchanted with the hosts' singing, beer traditions and… well, toilets.

1. 'The largest outdoor bars in Japan'

Tournament organisers are terrified that the beer-loving rugby fraternity will catch Japan unawares and drink the stadiums dry - and with good reason.

At the 2015 World Cup in England, fan zones and match venues sold 1.9 million litres of beer. Venues that also host football matches said the rugby crowd drank six times more, on average.

Image copyright Getty Images Image caption Rugby fans apparently drink six times more than football fans

But never fear: conscious that a dry bar equals miserable fans, tournament beer sponsor Heineken has stepped up production by 80%.

And for those too full of sushi to leave their seats, there's even better news: Japanese sports matches often employ roaming beer hawkers known as Uriko, and more than 1,650 will be on hand to serve the thirsty if the tension or the 25C (77F) heat get too much.

2. Anthem in Welsh? No problem

The Japanese aren't especially famous internationally as a musical nation - unless you're a fan of J-pop or you count karaoke - but when 15,000 locals serenaded the Welsh team with their anthem and the much-loved hymn Calon Lan during a training session, it brought a tear to red-shirted fans back home.

But Wales, who set up their pre-tournament camp in the city of Kitakyushu, aren't the only ones who've seen their culture beautifully reflected back at them.

Media playback is unsupported on your device Media caption Japanese children in the crowd at Kitakyushu stadium

Tournament favourites the All Blacks were treated to a welcome haka by Japanese schoolchildren.

And perhaps even more impressively, both the Maori and English verses of New Zealand's national anthem.

Image copyright AFP Image caption Children perform the Haka during a welcome ceremony for the New Zealand All Blacks team

3. Big men meet bigger men

The Japanese are keen to show off their own traditions as well as honouring their guests - and for the Irish team, that meant sumo.

The big lads visited these other big lads at an early training session, which player Tadhg Beirne praised as a "great morning out".

Sumo training typically takes place in silence - but England got the opposite at their official welcome ceremony on Monday, which opened with the booming beat of Taiko drums, commonly found in Japan's Shinto shrines and Buddhist temples.

4. Toilet tech trauma

From the sublime, to the sanitary: fans and players alike have been awed by Japan's incredibly high-tech toilets, which are known to flummox foreigners with their array of douches and drying options.

Image copyright Getty Images Image caption Japanese toilets are known to be incredibly futuristic

Features range from lid controls to seat warming, and a built-in sink.

Like a pal heroically passing toilet roll under the stall door, the BBC's Tokyo correspondent Rupert Wingfield-Hayes had some comfort for the confused on Twitter, via a graphic explaining the buttons.

"That's a very important piece of information" came one reply. "I shall share it with the people of Aotearoa New Zealand."

5. The Pokemon stadium of dreams

Sticking with the tech theme, fans watching England tackle Tonga on 22 September are in for a treat. The Sapporo Dome on the Japanese island of Hokkaido is a remarkable multi-sport stadium which morphs into a rugby venue thanks to a sliding pitch.

Image copyright Getty Images Image caption The Sapporo Dome is out of this world

For its usual baseball matches, the stadium has artificial turf and seats set around a baseball diamond.

But for the Rugby World Cup, it'll transform - Pokemon-like - as the baseball floor is rolled up and a natural grass pitch is rolled in from the outdoors, where it waits ready for use. The seats can be rearranged too, guaranteeing fans the best view.

It all takes eight hours (can't rush genius, friends), but the magic can be seen in action via this excellent timelapse video.

6. Mythological mascots

These characters are Ren-G, the official tournament mascots.

Image copyright Getty Images Image caption Ren-G are sacred lion-like animals that ward off evil

As you've no doubt perceived, they are shishi: sacred, lion-like animals from Japanese mythology. Legend has it they bring happiness and ward off evil. According to World Rugby, they also attract cash - at least for whoever runs the licensing programme.

At the 14 official merchandise stores, their image graces everything from furry hats to plasters. A mere US$1,849 (£1,490) will score you a pair of hand-made lookalike dolls. Serious bids only, please…

7. A volunteer army, aged 19-88

More than 400,000 overseas fans are expected to descend on Japan from 20 September - 2 November. To minimise the chaos, the host country has marshalled some 13,000 volunteers across the 12 venue cities.

At 88, Toshio Yasuda is the eldest of their number, while the youngest is 19-year-old Misaki Inomata, from Yokohama, who hopes to have a career in sports science.

All volunteers have been taught the history of the World Cup, and will be on hand to guide fans round the venues and nearby train stations.

8. Beating the weather with... shampoo

It's currently typhoon season in Japan, and organisers are tracking all weather patterns live as they emerge. In the event of match-wrecking conditions, they're prepared to postpone, relocate or cancel.

Image copyright Getty Images Image caption Balls to be soaked with... shampoo?

In the knockout stages of the tournament, affected matches would be rescheduled or relocated. But if an early pool match can't be played on the day, it will be declared a draw - which could produce unexpected results.

Some teams are especially determined to stay ahead of the weather. With torrential thunderstorms forecast for their opening game against Ireland on Sunday, Scotland have been practising using balls soaked in shampoo.

Wales on the other hand, are choosing to soak their balls with baby oil.