1. Swing-lo: the Japanese fans have the anthems covered
The Welsh Rugby Union were surprised and delighted to have a training session serenaded by the national anthem.
From a country of 3million the other side of the world they hadn't expected a huge turnout from home fans. However, during a training session at Kitakyushu a crowd of about 15,300 Japanese locals - in shades of Welsh red – piped up.
"It has exceeded all our expectations. But what has really warmed my heart is that it has shown how really strong the brand of Welsh rugby is," the Wales skipper Ryan Jones told the BBC.
2. Musical toilets: It's not just the fans who can hold a tune
Japan is famous for its advanced technology, yet some fans are already hitting the panic button.
The musical toilets with multi-button bidets are real.
Fans' twitter feeds have filled up with pictures of remarkable commodes, toilets with self-warming seats and cistern-top basins. Other visitors have been turning to the web for help and instruction manuals.
In a tournament that is sure to be full of trials, one of the biggest might just be spotting the flush button.
Fortunately Tokyo-based journalist Rupert Wingfield has come up with a guide:
3. Stadium tour: Technology spreads onto the pitch
The host nation has had to commandeer and retro-fit a number of venues to give them the appropriate number of pitches. However, in one stadium that's been an easy job.
The Sapporo Dome has a system that allows a grass pitch of any kind to be inserted directly into the stadium – through giant barn doors. It can change from a baseball stadium to a soccer pitch to rugby football at a moment's notice. As long as that moment is eight hours.
4. Beware the mascot
Tourists will already be familiar with the shishi, the fluffy lion-yeti cross mascots for the Rugby World Cup.
However, mascots are nothing new in Japan. Almost every town, business, and prefecture is represented with cuddly and sometimes not-so-cuddly champion.
Mondo Mascots is a Pokemon-like twitter feed set up to catch them all, as ugly as they come.
The Gajiro swamp monster from Fukusaki, for example, looks like your worst nightmare and is there to scare residents into good behaviour.
Disorderly sports fans, be warned!
5. Big in Japan: The other national sports
The growth of rugby in Japan has taken the world by surprise. (Looking at you, South Africa!)
However there are a whole stable of other sports in the island nation that you won't find anywhere else. Sumo being one of the better known Nippon-centric sports. These guys would make the national squad's front row look scrawny.
Irish lock Tadhg Beirne discovered this for himself in a recent bit of sight-seeing.
Kendo sword fighting and Hanetsuki (Japanese badminton) are some of the other unique non-ball sports that Japan has to offer.
6. The Haka travels
When the national squad arrived in Japan they were greeted by an adorable rendition of the Haka.
However, this was to be the first of many as the All Blacks were greeted again by another pint size war dance at the Kashiwa stadium.
The Haka seems to have been an informal part of training for the 13,000-strong games volunteers, as an iconic bit of rugby culture that everyone can get behind.
New Zealand games might as well be in front of a home crowd.
7. Beer is an international language
Many sports fans have been worried as to where they will source a half-time pie and pint.
It's tough stakes for pastry fans in Japan as the lack of meat pies is a well-documented by UK expat Gerry O'Donnell, who claimed to have been to first and only pie shop in Kyoto.
In Tokyo Kif Saint of the Punk Doily café has been serving up Kiwi pies since 2017, but nowhere near enough to meet the demand from 400,000 hungry rugby spectators.
Aussie footy fans petitioned the Victorian Government to help import savoury pies into the country ahead of the world cup.
However, Japan has its own range convenience food developed alongside large-scale spectator sports. It's a style of food known to the Japanese as "stadium gourmet".
Katsu is the sports stadium favourite and said to bring your team good luck via double meaning as both "fried pork" and "winner".
Also, gone is the worry of missing the deciding try while in the queue for drinks. The Japanese have a system of roaming beer sellers known as Uriko, who serve beer seat side.
