TOKYO -- After the water chestnut soup and the eggplant pickles, after the salt-grilled sea pike and the chilled tuna sashimi, Sumiko Kobayashi presents the guests at her gourmet restaurant here with the pie`ce d' re'sistance: a generous helping of steaming white rice.

To an American palate, it's just plain rice, hardly different from any other bowl of rice anywhere in the world. But Kobayashi says diners at her Akita Han restaurant are so taken with the particular brand of plain white rice she serves that they constantly ask her where they can buy it. Sensing an opportunity, Kobayashi has started selling small bags of the brand -- a northern Japanese variety called "Akita Komachi" -- for $2.95 per pound, an astronomical price even by Japanese standards.

"The flavor of our rice almost always becomes a topic of conversation," Kobayashi said. It's easy to believe, because the quality of the rice being served is a standard topic around Japanese dining tables.

Like wine snobs debating the merits of the latest presumptuous little Beaujolais, rice buffs here -- a category that covers a large portion of the population -- have devised a specialized language to differentiate among products that are largely identical. One brand of white rice might be said to have "good body." Another might be criticized because it "lacks luster."

But if the Japanese consumer has such an educated tongue for rice, and if Japanese-grown rice really is best, as this country's agricultural unions all maintain, why are Japanese rice farmers so terrified of permitting any rice to be imported? Why aren't this country's rice growers willing to go head to head against rice from the rest of the world?

That question has been raised repeatedly in recent months during the heated running debate over Japan's current policy banning all rice imports. The rather ambiguous answer from the farm community reflects the changing role of rice in Japan's diet and culture.

"We have confidence in our rice," said Masatoshi Shibata, a farmer from the northern town of Omonogawa and the chairman of a national farm union. "We are confident that any rice coming in from California or South Asia will not be as tasty as ours.

"But imported rice will be cheaper, and there are people today who will buy on the basis of price, not quality. If we open our market, we could lose those price buyers to the importers. Japanese agriculture cannot stand to lose any buyers at this point."

The 30-year-old Shibata, who farms a plot worked by his family for at least three centuries, is unusual in that farming is his full-time job -- a description that applies to only 5 percent of Japanese farmers today. In addition, his 10-acre plot is four times as big as the average Japanese farm.

But Shibata is a typical Japanese farmer in his conviction that high-quality Japanese-grown rice is clearly different from other varieties of white rice. When Shibata was given a blind taste test recently, he passed it with ease, differentiating between a top-of-the-line Japanese rice and a blend of ordinary, low-cost brands.

Passing the Taste Test There are at least three dozen brands of plain white rice on the market here. Names range from the prosaic -- "Everyday Rice," "Agriculture Ministry No. 22" -- to the poetic -- "Shining Peak," "Woven Bamboo," "The Glistening Moon," "Blue Sky Over Japan."

Many Japanese say they can tell the difference among these brands. Serious rice aficionados even say they can distinguish between a bowl of, say, Sasanishiki brand rice grown in Akita province and the same brand grown in Sendai province, a feat roughly equivalent to distinguishing between Florida and California orange juice in a blind taste test.

Prices among brands differ only slightly, because tight government controls limit the power of growers, distributors and retailers to rely on market price mechanisms.

With the latest round of world trade talks coming to a close, and with world pressure on Japan to open its markets to foreign rice, the Japanese have been showing more interest in imported rice. Several clubs and magazines have held blind taste tests to see whether Japanese consumers really can spot a bowl of rice from California.

Judging from recent tests in Osaka and Tokyo, they can. On taste tests pitting California white rice against various Japanese brands, the California product generally scores below the more popular Japanese rices. It's not that Japanese consumers find California rice detestable, but they seem to believe it's not quite as good as the best home-grown stuff.

Rice has been the staple food here since about the time of Christ, when settlers in the Yamato plain around present-day Kyoto learned rice paddy culture from Chinese visitors.

Today, virtually every Japanese home has a denkigama, an automatic rice cooker that keeps the food warm and moist all day. About 95 percent of Japanese households make rice every day, according to the national government, and most people eat it at least once per day.

Millions of factory hands and schoolchildren leave home each morning with lunch boxes containing the ubiquitous hinomaru, or "Rising Sun" lunch, a red pickled plum centered on a field of white rice, recalling the red sun on a white background in Japan's national flag.

In addition to the staple meal, rice is used here to make crackers, cookies, candy, sushi and of course sake, the deceptively powerful rice wine that is drunk in tiny cups but packs a big punch. The MOSBurger fast-food chain is doing strong business with its "riceburger," a small meat patty fried between two layers of rice. On almost every corner you can buy an onigiri, a snowball-like handful of rice with spicy pickles, seaweed or fish in the middle.

Consumption Dropping Still, total rice consumption has been dropping steadily for decades as the Japanese diet grows more Western. In the past 30 years, rice consumption has gone from 253 pounds per capita to 156 pounds. Since 1987, in a historic turnabout, meat and dairy consumption has exceeded rice.

Like everything else about the rice market, those statistics receive different interpretations from people on different sides of the rice importation question. Shibata, the young farmer, worries that "as rice becomes less important, people will be more likely to buy the cheapest, so they would take imports if they could."

But Sumiko Kobayashi views things very differently. "As people buy less rice, they're going to buy the highest quality every time," Kobayashi said. "That's why our restaurant is popular. My customers, they wouldn't even think about eating California rice."