It is a comfort food to which millions turn when in need of a carbohydrate fix. It has inspired popular manga titles and films, and expert reviews of closely guarded recipes adorn countless magazines, books and blogs.
Michelin may have declared Tokyo the greatest food city on earth last year, but you won't find a single étoile above the entrances to the thousands of restaurants serving Japan's de facto national dish: ramen.
The noodle-broth combination, usually topped with vegetables, a hardboiled egg and chashu pork, originates from China but became a source of sustenance in postwar Japan.
These days it is the food of the time-poor office worker, the student who demands satiation for their meagre yen, and, increasingly, for foreign visitors eager to forage deeper into Japan's culinary treasury – and all for about 700 yen (£5.20) a bowl.
The Japanese archipelago has inspired myriad variations, from the spindly noodles in miso broth in Hokkaido in the north, to a thicker version immersed in a pork-based soup in Kyushu in the south-west.
Aficionados insist that as much dedication goes into the perfect bowl of noodles as into a multiple-course kaiseki banquet, yet ramen, unlike its more illustrious counterpart, thrives on its street credibility.
Not even the queues that snake their way towards the entrance of Ramen Jiro, a legendary ramen chain, can deter ravenous Tokyoites.
In return for their patience, Jiro patrons are rewarded with huge bowls of chewy noodles suspended in fatty broth and adorned with hunks of pork. The only concessions to nutritional balance are the sliced cabbage and bean sprouts. At Jiro's testosterone-charged counters, the ability to finish a gargantuan serving is as much a test of masculinity as gastronomic endurance.
As Ramen Tokyo, an American blogger who has visited 350 ramen shops, warns: "Ramen Jiro is certainly not for those who are health conscious, and those of weaker constitutions can feel a bit queasy after eating there for the first time, especially if they force themselves to finish the whole bowl."
But the sheer number of ramen outlets means there are ample opportunities for those of us without abdomens of iron for induction into the cult of the noodle.
According to the most exhaustive guide, Ramen Database, Japan is home to around 20,000 dedicated restaurants, about 5,000 of them in Tokyo.
Many of the best are reviewed on English-language blogs maintained by foreigners, such as Ramenate, Ramen Adventures and this online tribute to all things ramen.
At the Shin Yokohama Ramen Museum, Chinese and Taiwanese tourists hop between noodle stalls from several Japanese regions, all set in a re-creation of Tokyo in 1958, the year Momofuku Ando invented instant noodles and turned Japan into nation of amateur ramen chefs.
Ramen's growing international appeal lies in its accessibility to the uninitiated. While a visit to an exclusive Japanese restaurant can be a nerve-wracking study in culinary etiquette, the ramen joint is the natural home of a more free-spirited epicurean. The rules are simple: slurp the noodles with gusto, gulp the leftover soup straight from the bowl, wipe your perspiring brow and earn the respect of your fellow converts.
Its maverick overtones have secured ramen an important place in Japanese popular culture: it is no accident that the frustrated hero of the popular manga Ramen Discovery Legend escapes the drudgery of his salaryman existence by running a noodle stall by night.
The dish looms large in Juzo Itami's 1985 "noodle-western" Tampopo, and in Ramen Girl, a 2008 film in which Brittany Murphy plays an American stranded in Tokyo who becomes a ramen chef under the tutelage of a strict, but benevolent, master.
"Ramen has no past," says Andy Raskin, the author of The Noodle King and I, in which he describes how Ando, a self-styled philosopher as well as noodle inventor, became his posthumous mentor.
"If sushi occupies a position in Japan's food hierarchy akin to that of haute French in the west, then ramen's culinary status hovers somewhere around the prestige of a sloppy joe.
"Unlike sushi or other traditional foods, there is no manual. So as a chef, you have to find your own way. As a result, there are so many variations and schools of thought. To me, that's what makes it fun and special."
Ivan Orkin, a New Yorker who runs a successful ramen restaurant in the Tokyo suburbs, agrees he would have struggled to make a living from any other dish.
His customers, he says, "are more open to the idea of an American cooking for them because ramen is a maverick cuisine. It's the only Japanese cuisine that doesn't have a rulebook. People who are otherwise uptight let their hair down when they eat a bowl of ramen."