As the hub of the Gokaido, the five roads radiating from old Edo to major centers around the country, the Nihonbashi district of the capital was long one of its most bustling areas.

Businesses of all kinds, from inns to moneylenders and clothes shops, crowded the narrow streets off the Nihonbashi River, with the last two represented today by the concentration of bank headquarters there and the nearby Mitsukoshi department store, founded as a humble kimono shop.

Nihonbashi, too, was the site of Edo's original fish market, and it was this that spawned what is claimed to be the country's oldest bento shop.

Back in 1810, the story goes, one Yoichi Higuchi opened an eatery in the fish market that he simply called Higuchi-ya. With a captive clientele of porters and fishermen, and ingredients arriving fresh from the sea all the time, it seems Higuchi made a good living. However, as his customers were all busy workingmen, they often only ate half their meal and wrapped the rest in a bamboo leaf to finish off later.

Perhaps it was this habit that gave Matsujiro, Yoichi's son, an idea that was to become a national phenomenon. Instead of carrying on with business as usual when he took over from his father in 1850, Yoichi cleared away the tables and renamed the business Bento-ya no Matsujiro (Matsujiro's bento shop) -- which soon became known simply as Matsuben.

Down there at the seedy end of Ginza, Matsuben continued catering to the same rough-and-ready clientele until the Great Kanto Earthquake struck in 1923. Among the victims of that natural disaster was the fish market, which was afterward rebuilt on newly reclaimed land further along Tokyo Bay at Tsukiji, where it remains to this day. With that, though, most of the shop's customers were gone and, just as in 1850, it was time to rethink the business.

So it was that Matsuben relocated to its current position, further from the river in Nihonbashi, nestled among the area's banks and company buildings. In line with that move, and with thousands of simple bento shops having sprung up all over the capital, Matsuben also changed tack to purvey a better class of lunchbox. This committment to quality led to Matsuben being appointed to supply no less than Mitsukoshi in Nihonbashi. Contracts with other department stores across Tokyo followed, and today a Matsuben bento can also be purchased at some major rail stations.

It is in large part Matsuben's faithful maintenance of its products' Edo Period taste that continues to underpin its success. In achieving this, a key ingredient is sugar, which is added in generous proportions to the boiled vegetables to give them a sweet, full flavor. As a result, unlike in cheaper bentos, this eliminates the need to add soy sauce to enhance the taste. Add to that octopus that is pleasantly chewy, crisp and firm bamboo, creamy potato, and shredded ginger and konbu (kelp) soaked in pungent soy, and the result is a treat for the taste buds.

Although Matsuben's bentos come in several different varieties, none contain meat -- nor, of course, preservatives. Currently, too, half the vegetables used are from Japan and the rest come from China, where, according to the current owner Junichi Higuchi, some (such as bamboo) are of a superior quality and availability. To further distinguish its bentos from the rest, Matsuben uses swordfish, which is more expensive than the likes of the salmon or buri (yellowtail) in your average box lunch.

Even though the higher costs of such ingredients are partially offset by Matsuben's slightly higher than average prices, Higuchi insists the profit margin per bento is small. "If you pay about 1,000 yen for a meal of soba noodles," he says, "it probably only cost the restaurant 20 percent of that to make the noodles. But it costs us a lot more to make our bentos, which we are selling for a similar price. Even if we give discounts, other bigger companies could still make bentos much cheaper than us.

"But I am not selling to those who just want to fill their stomachs at lunchtime. If that is all someone is looking for, I don't mind if they go elsewhere. What we are selling is actually a piece of Edo culture. We want to be able to choose our customers."

That said, Higuchi is currently pondering a move away from supplying the big department stores. "I have to get up very early," he explains. "Sometimes at 5 a.m., often at 2 a.m. It's a little crazy. We make between 1,000 and 2,000 lunchboxes every day. If I can move away from the big orders and broaden our local customer base, we can run the shop on a more reasonable schedule."

In thinking this way, Higuchi isn't simply looking toward a slightly easier life, but a longer one, hopefully, than his hard-working forebears -- none of whom made it beyond their mid-50s. At 31, the non-smoking, near-teetotal proprietor is in no rush to join them. However, despite studying law at university, Higuchi says he "never thought seriously about working in anything but the bento business." He took over Matsuben when his father died in 1997.

As a true Edoko, his main passion is the history and culture of his home city. Among other things, he is an avid collector of old postcards of the capital -- and especially of Nihonbashi -- for which he has paid from 100 yen up to 10,000 yen. In fact, as part of a special promotion Matsuben is staging on Dec. 19, he will be giving a reproduction postcard of a 1930s view of the bridge itself free with every special, swordfish bento purchased.

So to grab your taste of Edo at the old-fashioned price of 260 yen, you'd better get your geta on as the promotional bento that day are on a first-come, first-served basis -- and the last time Matsuben did this, on Nov. 21, all 100 lunchboxes were sold out in just 9 minutes.