The first known records of yuba – in Japanese cookbooks – didn’t appear until the 16th century. Yuba eventually made its way to the tables of the imperial court, where it maintained an aura of elegance and refinement, quite different to its status in China.

For more than 300 years, the ancestors of the shop’s owner, Tomizo Asano, have run the charming little shop, known as Yuba-han, which adjoins her home. Today, the family peddles the same rarefied recipe of yuba as its forefathers did.

In short, it’s a real treat. “You won’t find this kind of yuba anywhere else!” exclaims Asano, the ninth-generation proprietor.

Every morning, Asano wheels her products on foot to the two most exclusive Kyoto ryokans, or traditional inns, conveniently located across the street.

She also sells fresh and dried varieties of packaged yuba in her building, and insists that her customers try it in the simplest and most traditional way: by laying a brittle, silky sheet in a bowl, sprinkling it with soy sauce, and letting the soft, warm sampling melt on the tongue.

The simplicity of this serving reflects the historic role of yuba among the Japanese clergy. Kyoto is the global centre of Zen Buddhism, and monks have dined on yuba for hundreds of years as a replacement for meat.

Most historians agree that, in the ninth century, a legendary monk named Saicho made a trip to China and returned to Kyoto with yuba, tea and Buddhism. He introduced all three on Mount Hiei, a maze of forests and monasteries in north Kyoto, where his monastery still stands.

“Yuba never had the popularity that it did in China,” says Michael Ashkenazi, an anthropologist who studies Japanese food culture. “By and large, it always had this attribute of a very luxurious food.”

The Zen schools founded in that era paid close attention to whether monks ate meat and fish, and those sects were associated with the aristocracy.

Today, the ingredient is a staple of the city’s finest multicourse kaiseki dinners, a sort of haute platter of fresh foods such as sashimi, clear dashi soup, pickled vegetables and other carefully balancedside dishes.

At the city’s most epicurean restaurants, these dinners fetch up to US$1,000 each; even midpriced bistros charge at least US$100 per person.

But a handful of establishments, such as the Seike Yuba restaurant in the heart of Kyoto’s ancient textile district, are putting forward an unusual type of kaiseki with yuba as the primary portion.

The menu at this restaurant boasts three lunch and three dinner courses, priced between US$42 and US$115, and all of them consist of large portions of yuba in one form or another.

The restaurant’s matriarch, Tomoko Nakata, is known for getting creative with her mash-ups. Most meals include a smattering of sashimistyled yuba, yuba “steak” served on a sizzling platter, seasonal soya milk soups, and a slice of yuba served on top a small bed of rice and eaten like sushi.

Other, lower-priced venues frequented by university students use bean curd froth as a topping for udon, or cheap wheat flour noodles.

Some enjoy their yuba in shabu shabu, a boiling communal pot of vegetables and thinly sliced tofu. A yuba set lunch at Komameya is US$11, while the soya milk ramen with yuba at the popular Mamezen costs US$11to US$15.

Yuba also holds a niche among diners seeking a highprotein diet – and some say it’s a more robust alternative to tofu, its more available counterpart.

Japanese doctors recommend it to patients suffering from high blood pressure and diabetes. In its dried form, yuba contains 52 per cent protein, about four times that found in tofu.

That makes it one of the richest natural sources of protein around. But for Nakata, the owner of the Seike Yuba restaurant, marketing the delicacy is more about preserving this historical labour of love rather than nutrition or turning out a profit.

“No one knows how to appreciate yuba any more. We set up this restaurant to change that,” she says. “People just aren’t interested. They don’t know about it.”

The Nakata family’s mission has humble beginnings. In 1990, Nakata’s father began making and selling yuba from their home in a thatched-roof neighbourhood in the mountains of the surrounding prefecture.

Seven years ago, she decided to open Seike Yuba – with the help of a local charity – in a 130- year-old textile workshop which was slated to be demolished.

The historic building, renovated with moss gardens and spacious Zen-inspired decorations, enhances the fine dining experience.

The family is particularly proud of their province’s water as contributing to their success; because water and soya milk are the two main ingredients, a clean supply of spring water means their yuba is fresher than in other parts of Japan.

“Kyoto water is famous for its purity and high mineral content,” Nakata says. “The city’s food culture has developed around it.”

In Kyoto, it’s common to see locals, along with water connoisseurs from around the country, fetching water from wells and loading bottles of it on their bicycles.

For yuba restaurants, the difficulty is finding trained masters who know how to skim the hardened soya layer off the milk surface and prepare it for consumption.

Young Japanese apprentices once trained for around a decade to prepare cuisines including yuba, Ashkenazi says. Today, “they aren’t prepared to put up with that, so there’s a smaller pool of potential recruits”.