It is an obvious, perennial question, one that must pop into the head of every visitor within 24 hours of touching down at Narita, and yet a conclusive answer remains as elusive as the yeti. Having Googled the question, and read myriad conjectures, suppositions and wild guesses, I was still none the wiser, so I did as the ancients and took my quandary to my local hostelry.

Being a popular debating club for those with perennial questions bubbling away in the recesses of their minds, I’ve often found myself at the Worrisome Kilt in Ueno, debating some thorny topic with the regulars over a few bottles of Proper Job.

My question was taken up eagerly. The first theory I heard by way of explanation was that the pigeon toed stance otherwise known as uchimata 内股 is a result of the way that Japanese mothers carry their infants in a sling on their hip.

However, as I was quick to point out, this theory doesn’t hold water, because very few young mothers in Japan carry their infants on their hips (unless they’re planting rice, that is). Besides, carrying your infant on your hip is de rigueur in many parts of Africa, and yet the sight of pigeon toes en masse seems to be peculiar to Japan.

A second theory wasn’t long in coming. “It’s obvious,” said a Welsh giant, jabbing at my chest with a bony finger and breathing beery fumes into my face. “Uchimata is a consequence of the shape of the Japanese leg.”

He went on to explain that Japanese people have shorter calves than most people, and this makes their toes point inwards. I didn’t want to risk the giant’s wrath by openly challenging him, but I didn’t buy his theory either. Were it true, why would the condition affect so many Japanese women and so few men? Unless that is, Japan’s women have shorter calves than its men, a supposition I have found no evidence to support. As diplomatically as I could, I poo-pooed the giant’s theory too.

We were now stumped, but the lull in what had quickly become a remarkably lively debate, even by the Warrior’s stellar standards, was mercifully broken by the intervention of a well-informed medical student. His theory, related to that of the Welshman but rather more grounded in praxis, was that the prevalence of mass pigeon toed-ness is a consequence of seiza 正座, the practice of sitting on one’s calves (he also mentioned pechanko-zuwari ぺちゃんこ座り, or sitting on the floor with your legs splayed on either side of your body).

I was impressed - but not for long. One of the Worrisome Kilt’s veteran sceptics pointed out that the medical student’s theory would be plausible if sitting on one’s legs were still commonplace in Japan but, as even the most recent arrival will tell you, very few people sit on their calves or the floor anymore.

He was right. Sadly, the table and chair killed off the tatami mat a generation ago, and with it went the practice of sitting on the floor. Admittedly, a handful of diehards still insist on sitting on their calves while seated on a chair, but they are too few and far between to account for the prevalence of uchimata, which seems to be increasing rather than decreasing as the nation’s tatami mats recede into the shadows of Japanese history.

“Could it be that walking pigeon toed is in fact a conscious decision, made by women in an attempt to look cute?” a visiting Icelandic sociologist wanted to know. Though well-meant, her question spawned so many sub-questions and sub-sub-questions that for a time, the bar was thrown into a chaotic hubbub that only died down when the landlord threatened us with eviction.

Only slowly was the order necessary for reasoned debate restored. When I felt confident that my fellow drinkers were ready to proceed once more with our enquiry, I ventured that pigeon toes were in fact an affliction. Who, I demanded to know, could possibly find them attractive?

On this point, at least, my companions were of a single mind until, that is, the bar’s resident historian, who had until then maintained a dignified, if drunken silence, chose to pipe up with a theory that put the debate, and with it the bar’s clientele, to bed for the night.

“Pigeon toes are indeed an affliction,” he intoned grandly. “But that’s the point. Japan is a patriarchal society and, being patriarchs, its men like to see women looking disabled. Pigeon toes are an emblem of their inferior status, their limited ability, and their inherent weakness.” With that, he fell off his chair, which the assembled company took as their cue to go home.

“Does this mean that women only walk pigeon-toed while they’re in male company,” I demanded to know. “Do they revert back to a normal gait once in the privacy of their own homes?”

But it was too late. The bar was now quite empty, bar me and the fallen historian. The first beams of dawn sunlight were stealing through the shuttered window, and I was left with only my perennial questions for company.