Key Points:

The sight of two 150kg-plus sumo wrestlers colliding at full tilt is hardly the pinnacle of sophistication but there's no denying that Japan's national sport, sumo, is a grand spectacle.

The goal of the sumo wrestler, in between bouts, is to grow as large and strong as possible. How they go about this is less clear, but you can safely assume it has a lot to do with eating.

In a fight, the goal is to force the opponent out of the 4.55m-wide ring, or to floor any part of him other than his feet. Either outcome results in victory, though the latter puts those in the front rows at sumo stadiums at considerably less risk of being flattened.

Two fatties crashing head-on into each other causes the world to shake momentarily, while the air echoes with what Clive James described as the sound of colliding watermelons. The moment of impact has all the drama of a high-speed crash between two trucks and the crowd makes "oooh" noises accordingly.

Size clearly matters but it's not the be all and end all. Watching any bout at the Kokugikan, the sumo stadium in Tokyo, reveals sumo techniques other than the crash and bash. There's the push and slap _ often involving stiff arms to the throat area _ the grab and throw, the hold and lift/hump, the side-step and knock off-balance, and the I'm-not-losing-without-dragging-you-with-me tactic.

The lead-up often takes much longer than the fight itself and involves a number of traditions that allow the fighters to psyche each other out. They face each other for a moment, then retreat to their respective corners before coming together again for more staring at each other.

They do this while raising their massive legs high in the air before thundering it to the floor. This drives evil spirits from the ring because, I suspect, the sight of a Japanese giant, his leg raised, is enough to make anything run in the opposite direction.

There is also much slapping of hands and chests - traditionally to show your opponent a lack of weapons - and throwing of salt to purify the ring. The more theatrical wrestlers launch large handfuls of salt skywards, accompanied with a war-cry and much chest-beating.

In between these rituals, the referee calls out the wrestlers' names with all the reverence of announcing the next supreme ruler of the universe.

When the fighters have decided they've done enough staring at each other, they reach an unspoken agreement to start the fight. The green light signal appears to be when each wrestler has both forearms on the ground - they're surprisingly flexible for their corpulent size - and, remarkably, this sees most fighters out of the blocks at the same time.

Fighters clad themselves in flattering silk belts (mawashi) that hide their bits and tie their hair in a traditional top-knot; failure to keep the hair-do means being stripped of sumo status.

The sumo stadium is as grand as the bouts, but barely registers on a map of what is an overwhelmingly vast city, population 12.5 million (though it bulges to more than 35 million if outer suburbs are included).

Modern Tokyo is a shoppers' paradise (the city is far more affordable than it was five years ago, thanks partly to consistent deflation).

The skyline looks futuristic and includes skyscrapers that curve and buildings that scream at you in neon. Trendy areas bombard you with endless billboards and television screens of gargantuan proportions.

But the city-scape has plenty of variety. The streets surrounding the city's oldest temple, the Sensoji Temple, are filled with vendors selling everything from snacks, mobile phone accessories, samurai swords - even an ice cream parlour selling 32 different flavours, including kumara.

"Buddha is a businessman," explained our guide when asked why commercialism is allowed to thrive so close to a sacred site.

Downtown Tokyo also mixes the old with the new. A few blocks from the upmarket Shiodome Tower is a 340-year-old nature reserve, where visitors can roam perfectly manicured gardens against a back-drop of towering corporate buildings.

A stone's throw from the gardens is the frenetic Tokyo Tsjukiji Fish Market, the country's biggest wholesale market - no place for the careless or slow-footed. Immerse yourself at your own peril in the jungle of gas-powered carts, man-powered bicycles, trucks and wheelbarrows.

The action starts early, with ships dropping off cargo at the market entrance well before dawn.

The auctioneer takes centre-stage among the hordes, raising his arm and crying out suitably as the produce is sold off, while lines of frozen, impressive-looking bluefin tuna lie on the cement floor behind them.

A whole tuna - as long as a full-grown man and weighing up to 100kg - can sell for as much as 500,000 yen ($5800), while 30kg boxes of tuna - about $1400 are available for smaller dealers to bid on.

About 2000 tonnes of fish come through the market every day. Across from the auction area there are sellers elbow-deep in gills and scales, fins and tentacles, shrimp and all kinds of shellfish, sea urchins and tuna chunks. They use machetes, band saws and huge knives to slice up their catch.

"Baka. Baka," cried a gentleman on his bicycle in the middle of the ordered chaos, trying to wade his way through the hectic traffic. He had run into a wall of visiting journalists and, though few of us were familiar with the Japanese word for "idiot", the tone of his voice left nothing to be lost in translation.

Amid the constant mayhem, a man approached a seller cutting up a dark red tuna carcass. The seller sliced off a bite-size sample and handed it to the man, who promptly chewed, swallowed, and nodded his approval.

As he departed with his purchase, I motioned that I, too, wanted a sample. My limited Japanese meant I could only ask "Ikura desu ka?" ("How much?") while holding my hand to my mouth to show some form of eating action.

Eventually he sold me a container of sliced, fresh tuna for 500 yen ($5.80), enough to see me - and several others - through from a state of tuna-filled contentedness to tuna-filled nausea.

The edge of the market is less life-threatening, as a stream of carts and fish-carriers gives way to the odd truck driving off, taking produce to the masses. Outside the market are several restaurants selling sashimi (raw fish) that's just been plucked from the ocean, washed and served.

The market is one place where people mean what they say and aren't shy in saying it, but in the hospitality and retail sectors, there is a cultural obligation to be more polite than sincere.

The up-side of this is perfect courtesy. Every step inside a shop is greeted with a cry of "Irashaimase" (welcome), every exit with an "arigato gozaimas" (thank you). When leaving a hotel or restaurant, staff will face you until you are out of sight and bow if you turn to look back at them, even if this means holding a bow-pose as customers walk 50m before disappearing from view.

The downside - and this can be quite disconcerting - is that the Japanese can sometimes say one thing, but mean its opposite.

Air New Zealand's Japan and Korea general manager, Chris Myers, says real meaning can often be determined through context and cultural nuances. He tells of a deal where some New Zealanders were told by Japanese businessmen that they were having a few difficulties.

"That doesn't mean there are difficulties," Myers says. "It means there's no bloody way the deal is going through."

Even in a state of intoxication, the Japanese seem to maintain courtesy. This seemed to be the case at a karaoke bar in the trendy suburb of Ginza, where we found ourselves surrounded by tipsy Japanese businessmen and good-looking - meant sincerely - hostess girls intent on flirting, pouring drinks and enticing us to the microphone.

The girls were not shy with the make-up, nor about rubbing their hands over our thighs. Courtesy here appears to be doing what is expected of them.

The bar had a modern feel and even had its own resident opera singer.

Visiting such a bar is often routine at the end of a long working day. The Japanese on average work longer hours per week than any other nation, so you can see their need to unwind, entertain clients on the company credit card, and plunge themselves into various states of inebriation.

But while the Japanese struggle at times to break the politeness barrier, they have no qualms about expressing themselves through dress. This is nowhere more apparent than Harajuku Square, where the beautiful, weird and whacky come together to pose for anyone caring to look.

On a sunny, humid Sunday, a girl dressed in black, a padlock around her neck and her fringe covering half her expressionless face, held her hand to her face in signature pose before a scrum of photographers. Another, looking like something out of Dracula's closet, was shielding herself under an umbrella.

Hiding in a taped-off area, one group looked like they had stepped out of a Mary Poppins play, each dragging a small suitcase full of make-up behind them.

One man showed up in a dress, a necklace of pinecones and small goldfish bowls _ complete with fish inside them _ as earrings. Another, though not oddly dressed, danced for the crowd while 80s' beats played on a small ghettoblaster. He wasn't busking.

Fashion is of vital importance in Japan. There are the executives in their suits, the fairytale crowd, the Goths, the Emos, the weirdoes. There are those in leather pants, in knee-high socks, in mismatching knee-high socks. Some prefer short shorts, others short skirts. Some wear heavy woollen hats, despite the stifling humidity and searing sunshine.

There's the Louis Vuitton crowd, the Ralph Lauren devotees, the Prada champions. There are condom shops with fashionable rubbers that sit alongside cheaper ones that were so last year.

On fashionable alleyway Takeshita St, there's even a shop where you can buy the latest in canine attire. Items include jerseys, mutt-goggles, the latest Lee jeans and all sorts of trendy bags in which to carry your four-legged friend, lest it gets sore legs from walking.

It all leaves a wide-eyed and fascinating impression, but the rampant consumerism seems a tad excessive. While you end up admiring Japanese presentation, you can't help but wonder whether it's self-expression or sheer exhibitionism. Or both.

GETTING THERE
Air New Zealand flies direct to Narita Airport in Tokyo from Auckland and Christchurch daily. Return airfares start from $1776.

WHAT TO DO
Six sumo wrestling tournaments are held each year in Japan, lasting 15 days each. Three are in Tokyo at the Kokugikan Stadium in the suburb of Ryogoku. Tours are available for about 10,000 yen ($114), or make your own way there and pay 2100 yen ($24) for a general admission seat.

The Tsukiji Fish Market is in Tsukiji, central Tokyo. Tours are available but you can just wander in for free, as long as you don't get in too many people's way. The best times to visit are between 5am and 9am. The market is closed on Sundays.

Near the fish market are the Hama-rikyu Gardens (entry is 300 yen or $3.40) and the Royal Park Shiodome Tower (http://rps-tower.co.jp/english/). All rooms have free internet access.

Senso-ji temple is in Asakusa. Free entry to the temple. Look for the Thunder Gate entrance to the shops on Nakamise-dori (street).

Takeshita-dori and Harajuku Square are both in the suburb of Harajuku.

* Derek Cheng travelled to Japan courtesy of Air New Zealand.