TOKYO -- Yuppie American parents of preschoolers may think their kids get high-toned educations. But for sheer poshness, few if any American nursery schools can hold a candle to the one operated by Seiwa Education Co.

Located in Tokyo's upper-class Azabu district, the school picks up and drops off children individually -- in luxury Volvos. The entrance fee for each of the 160 attendees is $3,850, and monthly charges range up to $2,260. (Parents who forgo the Volvo service pay less). Twice a week, students receive English and French lessons. The children are served bottled water.

The example is an extreme one, but it illustrates a trend: Money is being lavished on Japanese children as never before, and companies are crowding into the business of providing them with expensive goods and services.

Parents still prod their offspring to excel in school lest they be left behind in Japan's hellish competition for prestigious colleges and jobs. But even after the parental pressure to succeed in Japan's pressure-cooker educational environment begins to build, evidence abounds that Japanese children still enjoy a generous share of their nation's current surge in costly consumer items and that businesses are eager to exploit this development.

Signs of Japan's kiddie boom are everywhere. Nintendo's "Super Famicom" computer game sold out almost immediately after it was introduced late last year, despite a price tag of $192. A Sesame Street theme park opened last autumn in a Tokyo suburb. The American retailer Toys R Us Inc. is planning to build 100 stores across the country.

A boom in the fast-growing Japanese economy may not seem like news, but what makes the one in this particular market remarkable is the fact that it is happening as the number of customers is shrinking at an alarming pace. Since the mid-1970s, Japan's birthrate has been declining to historic lows. The number of babies born has dropped to about 1.25 million a year, 20 percent below the figure a decade ago and 38 percent below the level 15 years ago. The average number of children per family is down to about 1 1/2, compared with more than four during the years immediately after World War II.

At the same time, however, the number of Japan's elderly is increasing, which translates into more grandparents per child -- and more doting attention -- than ever. "Fewer children are surrounded by more rich adults and that means that the money spent on each child increases," said Hideo Takayama, director of the Children's Research Institute.

As a result, although Japan's birth dearth has aroused fears that the nation will eventually be unable to support its aged population, it hasn't scared away companies like Seiyu Ltd. that see a lucrative business opportunity. Seiyu, a major department store group, opened a 2,100-square-foot children's specialty store in central Tokyo last December selling toys, clothes, books and software aimed at children from age 1 to 7. It was the company's first children's store and more are planned.

The competition among retailers to win a share of the children's market is being waged with the traditional Japanese devotion to pleasing the customer -- in this case, very young customers. Almost all Japanese department stores provide floor samples of toys for children to play with, but lately some stores have taken this idea a step further.

In October, Isetan, a major department store chain, opened a special children's section called Dr. Kids Town at its store in the Tokyo suburb of Kichijoji. The 10,000-square-foot area is designed like a small town, with individual shops providing clothes, videos, candy and other goods. It includes a play area filled with sponges for children to romp in, a miniature fire engine and a zoo of stuffed animals. On Sundays, actors perform for children.

Isetan's move followed a similar expansion by the Seibu chain, which features a new 44,000-square-foot section called Kids' Farm at its flagship store in Tokyo's Ikebukuro district. Smack in the middle of the clothing racks and toy shelves stands a hollow miniature mountain for tykes to race around. A clown provides entertainment.

Competition also is keen among manufacturers of children's goods; the rewards are considerable for companies that can gain an edge in divining the Japanese consumers' psyche. Take, for instance, designer clothes, which are important status symbols for the generation of young Japanese women now of child-bearing age.

Japanese mothers tend to choose the same brand of designer clothes for their kids as they buy for themselves -- or if not the same designer, then the same look or style. For the group-oriented Japanese, "Wearing the same brand or style of clothes means that families can feel they are sharing happiness and unity," said Mizue Hotta, editor-in-chief of Sesame, a magazine that features articles on children's fashions.

Such a buying pattern is a boon for designer clothing manufacturers, especially foreign labels that the Japanese favor such as Ralph Lauren, Burberry and Christian Dior. Domestic designers, though, also are cashing in on the desire by Japanese parents to deck out their children in prestigious attire. BeBe, a Kobe-based company with a line that includes girls' dresses costing about $150, racked up sales of $269 million last year, up 20 percent for the year before.

All this is not to say that Japanese parents are suddenly going soft; they always have treated their children with a curious mixture of indulgence alternating with strict demands for academic achievement. Typically, the emphasis switches to strictness when a child enters elementary school and begins facing fierce pressure to get into a top high school and top university so as to secure the best possible position in Japan's hierarchical society.

But even then, a child's life doesn't become completely monastic. According to a recent survey by the research group of the advertising firm Hakuhodo Inc., otoshidama -- the gifts of money that Japanese children receive from relatives on New Year's Day -- averages about $160 for a fourth grader.

The report quoted several children saying that in addition to their otoshidama and monthly allowances, they could count on their parents to spring for designer clothes or video-game software almost any time something struck their fancy.

In any event, the fervent ambition that Japanese parents harbor for their children has itself created a lucrative business opportunity -- providing after-school education.

It is not unusual for a 3- or 4-year-old Japanese child to attend several classes a week in subjects such as drawing, English, piano and gymnastics. As they get older, children frequently add subjects such as calligraphy and mathematics. Millions of youngsters, even preschoolers, attend juku -- private "cram schools" that offer preparation for the entrance examinations required by exclusive institutions.

"People are becoming less confident in the public schools, so the demand for private schools is increasing," said Shinichi Kawabata, president of Gakkyusha, one of the largest chains of juku.

The trend has been beneficial for Gakkyusha; its revenue has risen by about 85 percent over the past six years, despite the fact that the number of children under the age of 15 has been falling at 2 percent to 3 percent a year.

Not everyone is happy with such developments, however.

"For children over 10 or 12 who decide themselves that they should go to juku, that's understandable," said Goro Kohno, a pediatrics expert at the National Children's Castle, an educational and recreational center managed by the Child Welfare Foundation. But Kohno worries about the smothering effects of juku on the development of younger children who often have little choice about whether to attend. "Children need room; they need to be left alone sometimes," he said.

At least Japanese parents sugarcoat the pill more these days. According to an official of Miki Shoko, an Osaka area maker of designer clothes for women and children, sales of the company's ritzy "Miki House" label jump during the entrance exam period for private kindergartens and primary schools.

Special correspondent Yasuharu Ishizawa contributed to this report.