When Kami Hinokinai Junior High opened half a century ago in the picturesque northern village of Nishiki, Fukuyo Suzuki, then a young mother, remembers joining other parents on a warm May afternoon to plant pink azaleas in the schoolyard.

The azaleas are still here, though bare in the winter snow and, like the new occupants of the school, more fragile than they once were. In a nation grappling with a record low birthrate and the world's longest average lifespan, Suzuki, 77, is spending the daytime hours of her twilight years back in the halls of her son's old school.

The junior high, which ceased operation six years ago because of a shortage of children, now houses a community center for the elderly. Suzuki comes to pass her time sipping green tea and weaving straw baskets with other aging villagers.

``I never imagined this school would close and that I would be back here myself,'' said Suzuki, a farmer's widow who lives with her 52-year-old son. Like one out of four men in Nishiki, her son remains single and childless. ``Now, I hear our elementary school is going to close, too,'' she said. ``It's so sad for us. Children are vanishing from our lives.''

The change at the junior high in this shrinking village of 5,924 is an example of what analysts describe as Japan's greatest national problem, a combination baby bust and senior citizen boom. Indeed, next year Nishiki is set to pay the highest price for its shrinking population. Unable to sustain its annual budget, it will join a growing list of Japanese towns that have officially ceased to exist and have merged with a neighboring city.

In the aftermath of World War II, the rush to build a modern economy sparked migration from rural towns such as Nishiki to Japan's urban centers. But officials say the lure of the big city is no longer the key factor driving depopulation. For at least the past decade, the leading cause of the town's shrinking population base has been a disturbingly low birthrate.

Last year, 42 babies were born in Nishiki, the lowest number since the town was incorporated in the 1950s, while 75 villagers died, according to statistics. Nishiki's plight, analysts said, could be an omen of Japan's future.

The national child shortage, even as the population ages, is raising fears about Japan's long-term ability to maintain its status as the world's second-largest economy after the United States. With more Japanese choosing to remain single and forgoing parenthood, the population of almost 128 million is expected to decrease next year, then plunge to about 126 million by 2015 and about 101 million by 2050.

Many people are asking: Will there be enough Japanese left to participate in the economy in the years to come?

``A nation requires a certain scale in the population to continue its momentum, but in Japan, we are confronting a serious combination of a low birthrate and an aging nation,'' Education Ministry deputy director Kota Murase said. ``Our pension system is already being tested to its limits. And with fewer young people in society, the question is: How are we going to sustain the elderly and the nation's future? We don't have a clear answer yet.''

Japan's disappearing schools are emblematic of the problem. More than 2,000 elementary, junior high and high schools nationwide have been forced to close over the past decade. The number of elementary and junior high students fell from 13.42 million in 1994 to 10.86 million last year. An estimated 63,000 teachers have lost their jobs.

Even as the percentage of people over 65 steadily climbs, an estimated 300 more schools a year are scheduled to shut their doors over the next several years - including Nishiki's 122-year-old Kami Hinokinai Elementary School, whose final graduating class will leave in 2007.

``We simply can't go on as we are,'' Nishiki mayor Chiyoshi Tashiro, 55, said. ``We don't have enough children being born to continue as an independent village. It is sad, but it is our reality.''

The baby shortage is altering Japanese society and traditions. In Kisawa, a town on Japan's Shikoku island, elders at the Unai Shrine have long called out the names of newborns at their autumn festival for happiness and health. Last year, there were no new babies to announce.

The lavish department stores of Tokyo have begun eliminating their rooftop playgrounds, replacing them with cafes and picnic areas for adults and the elderly. Over the past decade, 90 theme parks designed for children have closed in Japan. In the same period, Disney opened a popular sea-themed amusement park just outside Tokyo that targets adults more than children and allows the sale of alcohol.

As many as 117 hospitals nationwide now have no permanent obstetrician due to lack of demand and a shrinking pool of obstetricians and gynecologists, according to a survey conducted last year by a medical society based in Tokyo. The number of hospitals in Japan with pediatric wards fell to 3,473 in 2000 from 4,119 in 1990.

The list of solutions is short and complicated. The most obvious - opening Japan to more immigration - is enormously controversial in a society that is 98.8 percent ethnically homogeneous and, in many respects, still markedly xenophobic.

Some farmers in Nishiki who have failed to find Japanese women willing to live traditional lives in rural villages have sought brides in China instead. But village officials said several of the Chinese women fled after they failed to win the acceptance of their new in-laws.

Although it is a national problem, depopulation is most severe in rural areas such as Nishiki, a proud farming and forestry town where the population peaked at 9,180 in 1956. Over the years, families left Nishiki, seeking better fortunes in Japanese cities. The population stabilized in the 1980s, but the birthrate began declining in the 1990s.

It has happened in part because towns such as Nishiki suffer from a shortage not only of children, but also of eligible women. When Japan's economic bubble burst in 1990, Japanese companies seeking less expensive alternatives to men began hiring women for contract and part-time jobs. Gender roles have changed as a result. With increasing financial independence, more women are avoiding marriage.

According to a poll released by Japan's Yomiuri newspaper, seven out of 10 single Japanese women say they have no desire to become wives - a role that in Japan still largely means staying home and raising children.

In Nishiki, daughters are now more likely to leave to seek work in big cities, while their brothers stay behind to claim their family inheritance rights. Single men exceed the number of available women by a ratio of about three to two.

``It's hard here,'' said Kazutsugu Asari, 47, an unmarried employee of the city's construction department. ``There are lots of single men but fewer women. And many are not interested in traditional lives. I can understand why the women would leave town. But I have an obligation to stay as the eldest son.''

Japan has tried just about everything to boost the fertility rate, or number of children per woman, which hit a record low of 1.29 in 2003, compared with 2.01 in the United States. Nishiki is offering cash awards to families that have more than one child, even sponsoring mixers to bring young couples together. But so far, most attempts have failed.

Kami Hinokinai Elementary School, where the number of students peaked at 266 in 1960, awaits closure. Today, there are 33 students left, 11 of whom will graduate this year. Only five new students will enter the school this year. Those numbers prompted the decision to shut Kami Hinokinai in 2007 and bus the remaining children to a school about 40 minutes away.

With no other children their age, the two girls and boy in the second grade have learnt to make do. Tatsuya Wakamatsu, eight, says he persuades the girls to play baseball with him at recess and after school. In return, he grudgingly agrees to jump rope with them. ``There aren't so many kids for us to play with in the neighborhood and sometimes the older kids tease us, so the three of us always play together,'' he said.

Adults take part in sporting events to help the students form football and baseball teams. Last year, first-grader Takuya Suzuki, seven, had to play two roles in the school play. ``I was a mouse and a grandfather,'' he said, laughing.

When a baby is born in Nishiki, it is huge news. Last August, Yuna Wakamatsu arrived in a part of the community where no child had been born for 10 years. Traditionally, only women would come calling, offering gifts of food and money. But the men also turned out this time, showering Yuna with so many gifts that they now fill most of one room in the Wakamatsus' wood-frame home.

``They all wanted to see the face of a baby again,'' said her beaming grandmother, Tazuko Wakamatsu, 59, who takes care of the infant because both parents work.

In Nishiki, the last pediatrician switched careers in the 1990s, becoming a geriatric specialist. The nearest doctor for Yuna Wakamatsu is almost an hour away in bad weather. ``But I suppose there is nothing that can be done about it,'' her grandmother said. ``It's just how it is.''

THE WASHINGTON POST