Fish they eat raw. Seaweed is their idea of a gourmet treat. They breakfast on fish soup and sticky rice with pickled vegetables. And while we think there's no snack like a packet of crisps, they will chew contentedly on a bag of dried cuttlefish.
Yet, slowly and surely, a cult for Japanese food is growing in Britain. In London there are now some 70 Japanese restaurants, and more are opening all the time. But the most important contribution to bridging the gap between our two cultures is the Yaohan Plaza, the largest Japanese store in Europe, which has opened in Colindale, north London. 'All Japan under one roof', they boast. The complex of shops includes a Sega games centre, supermarket, seven food bars and two restaurants.
Walking along the aisles of the food hall you find yourself looking at ingredients which are completely alien to us: seaweeds, dried fungi, rice wines and vinegars, pickled salty plums and cherries, bamboo shoots and bracken shoots, white bean curds and salty brown bean paste, fish in every form, fresh and dried.
Some of the preserved fish are so tiny you wonder what Japanese fishermen are using to catch them with. Mosquito nets, very fine denier nylon stockings?
Noodles seem to be among the few familiar items. Then you notice they are not only made of wheat and rice, but from mung beans, from buckwheat and, according to the label on one packet, mugwort.
It's not just the ingredients, but the whole food culture that is alien. 'The difference between the British food culture and the Japanese,' says Len Landers, a spokesman for the Yaohan Plaza, 'is that Japan has a food culture and we don't' Eating raw fish, for example. But the Japanese only eat the freshest raw fish, which explains why the fish in the chill cabinets at the Yaohan Plaza is so expensive. A single fillet of mackerel costs pounds 1.70, when that would buy you several fillets at your local fish shop.
Here is a big difference in food culture. There is no limit to the degree of freshness they will pursue, though we've come some way from the spirit of the first Japanese restaurant which opened in London some 20 years ago. Eating here was a ceremonial affair, for we took off our shoes to sit at ankle-high tables, while kimono-clad waitresses with elaborately coiffed hair knelt beside us to replenish our Lilliputian thimbles of sake (rice wine). The main course was carp, served whole on a bed of beautifully carved vegetables, the back marked with cuts, thin strips ready to be plucked off with chopsticks and dipped into soy sauce.
Our hosts explained that we were to eat sashimi, raw fish, and to show just how fresh the fish was they dribbled a drop of sake into the carp's mouth. To our astonishment, not to say horror, the fish gulped. It was still alive.
In deference to British sensibility, you cannot expect to find this dish on the menu these days - though you would in Tokyo, where it is known as ikizukuri. It is described in A Look into Japan, a pocket book published by the Japan Travel Bureau, as 'a whole fish, sea bream or carp, carefuly sliced so as not kill it, and arranged on a bed of garnishings so it looks as if it is still in its natural state.'
This is all very well, but visit the Yaohan Plaza and you won't see the Japanese eating any of this exotic stuff. For one thing, raw fish is extremely expensive, taking account of both the premium cost of obtaining it sea-fresh, as well as the expertise and skill required to prepare it, served prettily on a plate or in sticky, vinegared rice rolls, sushi.
Rice is the heart of the Japanese soul (gohan, the word for rice, is also the word for food) and it is eaten at every meal at home. But the noodle bar is where working people eat when they go out. So the Japanese families on weekend shopping expeditions to the Yaohan sit down in the food hall to slurp a huge bowl of broth and noodles, with vegetables and teasing morsels of squid and dried abalone (like a large scallop).
The noodle bar, in fact, represents the changing face of Japanese food in Britain, for the most recent restaurant success has been the Wagamama off Tottenham Court Road, in London, where you queue to eat simply and cheaply at long tables.
At the other end of the social spectrum the elegant and expensive Japanese restaurants designed to service Japanese businessmen are strangely subdued. Polished chefs and stylish waiters play to empty houses.
The grandest new restaurant, The Mitsuri, a superb teppanyaki restaurant (performance cookery at your table by showy chefs) has made a ghostly start while its neighbour in Bury Street, Sir Terence Conran's Quaglino's, packs in hundreds.
There is a good reason for this: the recession in Japan. Many of the higher-salaried Japanese executives on the biggest expense accounts have been recalled. These shock troops were the spearhead of the commercial invasion of the last decade, Japanese merchant adventurers who poured into the UK to staff outposts of their empire, such as banking, the motor business (the Toyota and Nissan factories), electronics, television, video. But now their numbers are starting to fall, though there are still 50,000 Japanese living in Britain (30,000 of whom are in the London area).
Can Japanese food ever take its place in our affections alongside Indian, Chinese, Thai, Greek and Italian foods? The aesthetic beauty of their food display has long been an influence on one of our leading chefs, Anton Mosimann, who also believes their cooking is healthier than ours (they use no dairy products). Innovative chef Alastair Little is one of the few who comfortably uses Japanese ingredients - particularly wasabi, the hot horseradish-like mustard; daikon, the large, long white radish; mirin, a sweet rice wine for cooking; and bonito flakes, shaved from dried tuna.
The ingredients may be unfamiliar but the Japanese cook's palette of flavours is not. They balance sweet and sour, salt and bitter. Indeed the ubiquitous Japanese pickled plum, umeboshi, is an object lesson in taste and sensations, at once sweet and sour, salt and bitter in a single mouthful. The grammar of Japanese cooking is actually simple. Here we offer some useful tips and some recipes for the home cook using fairly easily obtainable ingredients.