Lettuce. Let us raise a glass to lettuce.

There’s a village in Nagano Prefecture called Kawakami — nothing, nowhere little place, deep in the mountains, far from the main road, population 3,960. Why does Shukan Gendai magazine devote three full pages to profiling it?

There are reasons.

One: It’s Japan’s richest village. Median annual income: ¥25 million.

Twenty-five million! How, why? What’s the cash crop — lettuce? Lettuce indeed, “as far as the eye can see.”

Two: Kawakami nurtures one of Japan’s healthiest and longest-living populations. Lettuce is good for you, of course. So is prosperity, short of gluttony. So is working in the fields, when it’s not backbreaking.

Three: Kawakami’s young people don’t migrate en masse to the cities. There’s a future here.

This is not typical. In fact it’s astonishing. Japan’s countryside is in grave danger. Rural populations are shrinking and aging. The nation seems on course to compress itself into one vast Tokyo.

What’s a dying community like? In April, the daily Sankei Shimbun described one — the port of Ryotsu, on Niigata Prefecture’s Sado Island. The main shopping street, a kilometer long, has 100-odd shops, maybe a dozen of which are still in business — a very attenuated business, if the number of visible shoppers is any indication. In 1950, the population was 126,000; now it’s 61,000. After dark it’s dark, not only the streets but many of the houses. They’re vacant, uninhabited, abandoned.

In 1950, 6.6 percent of the population was 65 or over; now, 37 percent is.

Ryotsu is rural Japan in microcosm. Kawakami, today an anomaly, may symbolize rural Japan’s potential. In 2009, Mayor Tadahiko Fujiwara published a book titled “Farm Village with a ¥25 Million Average Income.” Naturally, the media pounced on it, and there was Kawakami, blinking uneasily in the floodlights. The media got it all wrong, Fujiwara complains to Shukan Gendai. They focused on the money, as if that was all that mattered. What did he expect, given his book’s title? But full pockets, he insists, are secondary to “satisfied hearts.” Very likely — but it’s disingenuous to imply there’s no connection.

Fujiwara, 76, is old enough to remember the poverty that was once taken for granted, when local rice growers were too poor to eat their own rice. Surrendering it to their betters, they fed on coarser grains. The turning point was the postwar American Occupation. The Americans wanted lettuce, and recognized in Kawakami’s cool, dry climate an ideal environment for it. The Korean War increased demand. The Americans left; lettuce remained. Japanese diets were Westernizing, and lettuce, healthy, delicious and mildly exotic, became the Western vegetable par excellence. Last year, Kawakami shipped 60,000 tons of it to domestic markets, reaping ¥16 billion.

Shukan Gendai’s reporter is struck by the health and vigor of the elderly farmers busy in the fields. Not that all the farmers are elderly — 10 percent of them are in their 30s and 20 percent in their 40s, according to government statistics, as against national averages of 3.2 percent and 5 percent respectively. But 63 percent of local people over the age of 65 still work, and it’s not unusual to see people in their 70s and 80s hard at it, particularly in summer when “hard” is no understatement. Work — harvesting, shipping planting — starts at 2 a.m. and proceeds by the light of truck headlights. It’s home at last around 5 p.m. for bath, drink, dinner and — very early by city standards — bed.

In winter, the relatively slack season, some jet off to Hawaii or Thailand but others, schooled in harsher times, refuse to let prosperity spoil them — they head out to jobs at ski resorts or factories.

What’s in all this for a young person? “In lettuce farming, you earn in proportion to your efforts,” says Hirotaka Kida, 22. “Young people like that.”

Kida left for schooling (junior high school is as far as the local system takes you) but came back after graduating, eager to get on with the business he knew. “In Kawakami, unlike the big cities, people help each other out, whatever comes up.” Nice, but — “there are no convenience stores, no karaoke places” and the nearest city is an hour’s drive away. You learn to enjoy family and neighborly company. Marriage is a problem too, because however attached young men are to the place, young women get restless and migrate. A campaign to interest city women in moving in and possibly marrying locally is meeting with some success. The best way to appreciate the country, it seems, is to first get fed up with the city.

And who doesn’t get fed up with the city? The expressions we use to describe life there — “rat race,” “concrete jungle” — say it all (or at least seem to, when you’re in a certain mood). This month the Asahi Shimbun ran an amusing two-part piece by staff writer Kotaro Kondo on his own flight from urban stress. “A certain mood” was decidedly upon him. Friends of his had lost their jobs. What if it happened to him? What would he do? Tokyo-born and bred, he had no country skills, knew nothing but pavement and bright lights, could scarcely imagine a livable alternative. But, turning 50, he decided the time was ripe. Requesting a transfer to a rural bureau, he was assigned to rural Nagasaki Prefecture. Journalism would continue to be his trade, but he’d procure a small rice paddy, work on it early mornings, and grow enough to feed himself.

One thing Japan has no shortage of is abandoned farm land. Kondo got his paddy; a neighbor farmer agreed (not without bemusement) to be his mentor; and he struggles on, gamely learning the basics of a way of life thousands of years old and yet all but out of sight and mind to the suited, blinkered stokers of the modern economy.

“While the whole archipelago goes mad over the World Cup,” he writes, “you must picture me, bent over my narrow (mountain) paddy, shoving rice seedlings into the mud.” And there we must leave him, hard-pressed symbol of renewal, self-discovery, and the stern rewards of getting your hands filthy in the good earth that feeds us all.