Among cuisines, only French cooking has been distinguished as a national culinary tradition. Other picks by UNESCO for its World Heritage list, such as food from Mexico and Turkey, are more specific dishes. Washoku embraces seasonal ingredients, a unique taste, time consuming preparation and a style of eating steeped in centuries of tradition. At its heart is savory "umami," recognized as a fundamental taste along with sweet, sour, salty and bitter.
"That's a delicate subtle taste. But younger people can't even taste it anymore because they're too used to spicy oily food," said Isao Kumakura, president of Shizuoka University of Art and Culture, who is leading the drive to get washoku recognized. "It's Westernization. Japanese should be more proud of Japanese culture."
Kumakura believes UNESCO recognition will send a global message and boost efforts to save washoku, a fight that faces serious challenges.
Annual rice consumption in Japan has fallen 17 per cent over the last 15 years to 7.81 million tons from 9.44 million tons, according to government data.
Fast-food chains have become ubiquitous in Japan, including Krispy Kreme, Domino's Pizza and the perennial favourite McDonald's. Their reasonable prices and fast service are attracting the stomachs of the workaholic "salaryman" and OL, short for "office lady."
As washoku dims in popularity, fears are growing the community ties it historically stood for may also be withering, such as cooking together for New Year's and other festivals.
Those are traditions closely linked to family relations as defined by home-cooking — almost always the taste of mom's cooking, or "ofukuro no aji," as the Japanese say.
Yasuko Hiramatsu, mother, housewife and part-time translator, learned how to cook from her mother and grandmother, although she also relies on several cookbooks and watches TV shows to beef up her repertoire.
One of her favourite dishes is ground beef and potatoes cooked in soy sauce, sake and sugar, that she says has a reputation as the way to grab a man's stomach, and thereby his heart.
Both her husband and son love her "nikujaga." But it's a close call whether that recipe fits the strictest definitions of washoku, which is generally more about fish than meat.
Hiramatsu is old-style in making tsukemono from scratch, using "nuka," or fermented rice bran, from her grandmother's recipe to replicate the taste that runs in her family. She sometimes doesn't have time and resorts to packaged stuff from the supermarket. But that's not the ideal.
"Of course, sometimes I eat out and get French fries, but this is what has been eaten for the longest time," she said of her home cooking. "It must be something in our blood."
Washoku is always about rice, miso or soy-bean-paste soup, "tsukemono" pickles, and usually three dishes — perhaps a slice of grilled salmon, broth-stewed "nimono" vegetables and boiled greens. Umami is based on flavour from dried bonito flakes and seaweed, Japan's equivalent of soup stock.
Washoku is also about design. Fancy ceramic and lacquer-ware come in varying sizes, textures and shapes. Food is placed in a decorative fashion, sometimes with inedible items for effect like an autumn leaf.
Pieces of food may be cut into flowery shapes or carefully wrapped around other food, tied like a package with an edible ribbon. Recipes celebrate the seasons by focusing on fresh ingredients.
Kenji Uda, 47, the chief chef at Tokyo restaurant Irimoya Bettei, where he makes blowfish sashimi and crab cooked in rice, says he was 17 when he decided to devote his life to washoku.
"Japanese food is so beautiful to look at," he said. "But it takes a lot of time. People are working and busy, and no longer have that kind of time."
The exodus from washoku is apparent at Taiwa Gakuen, a Kyoto-based school for chefs, where the biggest number of students wants to learn Italian cuisine, followed by French, and interest in washoku is growing only among overseas students.
Seiji Tanaka, who heads the school, hopes the UNESCO decision expected at meeting in Azerbaijan this week will help draw Japanese people back to tradition.
"It's endangered," he said.
Tanaka believes the survival of washoku is critical because it's linked with what he sees as the spirit of Japan, especially the family.
"The 'wa' in washoku means harmony," he said.
In proper Japanese dining, the phrase "itadakimasu," or "I am going to receive this," is uttered, preferably in unison, at the beginning of a meal; "gochisousama," or "thank you for the meal," ends it.
Different from saying grace, the custom expresses gratitude not only to the chef but for the blessing of having food on the table — the grace of nature.
But even washoku experts say you shouldn't feel guilty about not eating it three times a day.
Kumakura swears eating with chopsticks — daintily picking each bite-size serving, never piercing — is a symbol of Japanese-ness. But he acknowledges he often has toast and eggs for breakfast.
"Just please try to have washoku at least once a day," he said with a laugh.
Follow Yuri Kageyama on Twitter at twitter.com/yurikageyama