Monique Roffey visits Yoahan Plaza, a space capsule masquerading as a Japanese supermarket
Beautiful, but weird. The vacuum- packed boiled gengo nuts could have been delicate alien pods Fedexed here from another world. So, too, could the bright magenta octopus parts and the lime-green gelatinous seaweed gook in a plastic tube. But no, they are very staple everyday cooking ingredients on a north London supermarket shelf. A Japanese supermarket.

Actually, The Plaza is more of a hypermarket cum shopping mall cum cultural space-capsule situated at the end of the Edgware Road in Colindale.

It's a culture capsule which starts in the car park. Japanese Muzak fills the air, but it is not until you look up and around you that you will spot the giant speaker sentinels responsible for the eerie greeting. Then, as you enter the plaza, you are welcomed by a soothing electronic female voice emanating from a hidden Tannoy (it seems odd that anyone could truly find this welcoming). But once inside, for a few hours, you find you are in a different world.

We started in the huge Japanese supermarket downstairs.

"Look, this could be a Matisse," said my friend Selby, pointing to a packet of noodles. The packet, like everything in the supermarket, was exquisitely designed. Teas, coffee, sweets, biscuits everything seemed too prettily packaged to buy. And those were just the familiar food items. Many other things seemed, like the gengo nuts, as if they'd been imported from another planet. Bags of bright pink powder, slice plant roots, bottles of green tea ... And then there was the fish counter.

Rows of glittering sardines skewered through the mouth on a green plastic prong and display-wrapped on flashy blue disco paper. Mounds of silver whitebait, racks of delicately laid out prawns, enormous exotically filleted fish. It all looked too beautiful to touch.

In fact, to the average Western customer, knowing what things are and what to do with them is a major drawback to shopping at this supermarket. Though most items are also labelled in English, this doesn't help much as the English name for something Japanese still doesn't explain what it actually is.

Everything seems so unfamiliar that you can't just toss a few ingredients into your shopping basket in the hope of whipping up a quick stir-fry later.

When I asked the plaza's press spokesperson if my reservations were common, it was a relief to find they were. "We do find other people have similar problems," agrees Miyuki Hazzard. "But this is something we're working on. It's very hard to understand the Japanese language and without a basic knowledge of Japanese food it would be difficult to know what you're buying. We're thinking of putting more detailed descriptions of what things are on packages."

In the meantime, what they do have instead, are some rather strange and off-putting waxed replicas of various "foods". At the sushi bar, at the cake shop and at most stores in the large food hall near the supermarket, you will come across waxed versions of dishes on the menu. Waxed plates of noodles stand next to paper cups of three-year-old coffee with the word "coffee" written on them. Exact replicas of the "egg and eel lunchbox" are carefully laid out.

But what isn't on waxed display is even harder to work out. At the kebab stall I found out just in time that a Baigai was a snail kebab. For the squeamish and those (like me) with immature palates, asking what things are is a must.

"Sixty to 70 per cent of our customers are Japanese says Miyuki Hazzard. "Only 15 per cent are British. The interest in cooking Japanese at home isn't as widely known as Chinese food in this country," she explains.

So popular is the shop with the Japanese community in fact that Japanese people drive there from as far away as Manchester. They come once or twice a month and stock up on everything. The British, however, "spend very little" when they come. This might be due to ignorance, but also because the prices at the Yoahan Plaza, due to import tariffs, aren't exactly cheap.

The plaza opened in September 1993, billed as "Europe's largest Oriental supermarket," but it is not unique. It is, in fact, part of a major international conglomerate. Four hundred and twenty nine similar stores exist in 16 other countries (220 in Japan). The first store, which opened as a village greengrocer in Japan in the 1920s, spawned a chain across the country which in turn spawned a global mega-chain of monster Yoahan Plazas across the world (the world Yoahan combines the word greengrocer and "yoaya" with "Hanjiro" the name of the shop's founder). The company has 20,000 employees worldwide, 300 million customers a year and projects to make pounds 285m by 1997 - big business.

Apart from the supermarket and food court the other main attractions are a massive computer games room, a Hello Kitty shop, a colourful but entirely Japanese book shop and a store selling state-of-the-art hi-fi's, VCRs and the kind of kitchen gadgets most housewives would die for. I spotted a plug-in bread-making machine - you just pop the ingredients into it, leave it overnight, and hey presto, perfect fluffy white loaves of bread in the morning.

But whether it's for one of these, some green tea or a Hello Kitty handbag, the Yoahan Plaza is worth a visit. The only problem is, whatever your shopping list is, it's bound to expand. "Take a credit card," my friend advised before our visit. Or on second thoughts, don't.

The Plaza is currently holding a huge fair of Japanese antiques and objets d'art, till 1 Oct.

Yoahan Plaza is at 399 Edgware Road, Colindale, London NW9. Opening times: 10 am-7 pm Sun-Thurs; 10am-8pm Fri, Sat.