45 per cent of young Japanese women aren't interested in sex.

When I visited Japan a few years ago, there was one thing that stood out from all the other, mostly European countries I had ever visited – and it wasn’t the temples in place of churches, or the Hello Kitty vending machines on every street corner.

It was that young people did not indulge in public displays of affection. Whereas in France it was not uncommon to see young people – or even not-so-young people – engaging in behaviour that would probably be called “dry humping” in Australia, in Japan I rarely saw young couples even holding hands.

Perhaps that was why I wasn’t surprised when I saw the following headline on The Guardian: “Why have young people in Japan stopped having sex?” Yep, that’s right. Statistics indicate that under-40s in Japan are “losing interest in conventional relationships”. Indeed, singles are at an all time high.

Millions across the country aren’t dating – and indicate that they have no desire to be. Almost as many people express no interest in having sex. A survey conducted in 2011 found that 49 per cent of unmarried women and 61 per cent of men were not interested in a relationship. That was an increase of 10 per cent from five years previously.

A further study from the Japan Family Planning Association found that 45 per cent of women between the aged of 16-24 said that they were “not interested in or despised sexual contact”. For men, 25 per cent said the same thing.

There could be any number of reasons for what appears to be Japan’s declining interest in romantic and sexual relationships. Some theories include the fact that Japanese men may feel less safe in their capacity to earn and provide for a family, as job security has waned.

Conversely, women have become more career driven, and are less likely to enter into a relationship when they know that marriage and children will – in the eyes of their employers – mean the end of their career.

The World Economic Forum ranks Japan as one of the worst countries in the world for women in terms of economic participation and political participation – and part of this is due to the difficulty women face in continuing their in career after childbirth.

On top of this, religious observance means that many young people will not live together or have children out of wedlock. And all this is before you even consider the fact that the economic cost of raising children is rising steadily.

Other explanations include the numbers of Japanese youths who are “shut-ins” – or as they are called in Japan, hikikomori – and do not seek contact with anyone, let alone a romantic partner. Social media and networking has also been blamed, as Japan’s technologically-savvy youth communicate more and more online – but less in person.

The sekkusu shinai shokogun – or so-called “celibacy syndrome” – that Japan is currently suffering from has future implications, too. The birth ate has been dropping steadily for the past decade, and it’s population – currently of 126 million – may shrink by one-third by 2060. Fewer babies were born in 2012 than ever before.

This will leave the country with a significant ageing population – and fewer young people in the workforce. The Guardian mentions a particularly alarming statistic: more adult incontinence pants were sold in 2012 in Japan, than nappies for babies.

Still, it’s not all doom and gloom. The Japanese National Institute of Population and Social Security Research study also found that 90 per cent of unmarried Japanese people do intend to eventually marry.

It is worth noting, however, that the danger that these statistics represent may have been somewhat exaggerated. Slate points out that the numbers of people in relationships and having children, is actually fairly similar in the US. In fact, birth rates are falling the world over (except in sub-Saharan Africa).

Slate points out, “Japan is simply facing a more acute version of a trend the rest of the world is also experiencing.”

But the fact that so many young men and women would describe themselves as “not interested in or despised sexual contact” is still a worrying statistic: if not for the sake of country and its economic prosperity, then for the emotional wellbeing of the youth.

Relaxing social norms, and young couples starting to feel okay displaying affection in public, might be a place to start.

Are you more concerned by falling rates of reproduction – or the idea of over-population?