The grounds of Tokyo’s Yoyogi Park have been colonised by beautiful youth: women and men beneath the cherry blossoms surrounded by bottles of wine, sake and shochu, cases of beer and plastic bags stuffed with finger foods – drinking, playing games and sharing smartphone screens as the buds bloom and fall.

Hanami (flower-viewing) parties are a centuries-old rite of spring, a national symbol of life’s beauty and brevity. But as I walk by them this month, I can’t help but wonder if any of the pink-faced revellers are hooking up, or even care enough to try.

“Sexless Japan” is now a reliable media meme. Bolstered by a plummeting birth rate and an ageing population (leading to dire predictions of a future Japan devoid of Japanese), this portrait of the nation’s celibate society has been further enhanced by a paradox: Japan’s cultural imagination is embedded with erotic imagery, from 17th-century shunga woodblock prints to what non-Japanese today often mistakenly call hentai (perverse) pornographic manga and anime. The sex lives of the Japanese, the story goes, have been almost entirely sublimated.

I once wrote about this phenomenon (sekkusu-banare, drifting away from sex) on this website, and talked about it in a BBC documentary called No Sex Please, We’re Japanese. Both times I was careful to imply what is now obvious: it isn’t just happening in Japan.

Recent reports from the US, UK and Germany also show dampening sex drives among the young, postponed marriages, fewer babies being born. Dimmed economic prospects and financial insecurity thwart physical desire, while greater access to online porn, dating sims, games and the dopamine highs of social media siphon away desire’s fuel: time and money. But regardless of their passports, the primary inactives are men.

In Japan, virginal, sexually uninterested males have been saddled with pejorative labels: soshoku danshi (passive grass-eaters), otaku (asocial geeks), and at the darker end, hikikomori (shut-ins living with and off their parents). At best, they are portrayed as awkward loners raised in the afterglow of Japan’s postwar boom, redeemable only through meagre acts of chivalry – a stereotype spawned by the 2005 domestic hit movie, Train Man. At worst, they are hopeless symptoms of the country’s humiliating irrelevance. China is rising, the US is moving on, Japan is left behind.

The University of Tokyo’s latest study of Japan’s “virginity crisis” focuses on financial, regional and generational data. No surprise: the majority of the population’s sexless men (one in four young adults, as of 2015) are not gainfully employed. They’re either jobless or work part-time and live in smaller cities or suburban/rural areas.

Money and mobility matter to women, and these men have neither. (Data for same-sex couples in Japan is not yet available.)

What is striking is the comparatively high number of young adult Japanese who, well into their 30s, have had some sex but gave it up, and now have no interest in finding an intimate partner at all. Dr Peter Ueda, one of the study’s co-authors (and, like me, a “hafu”: half-Japanese), tells me that this is where cultural norms may be at play. Matchmaking (omiai) persisted in Japan through the boom years of the 1980s, when the task shifted from village elders to corporate managers. In the 21st century, modernisation, westernisation, and the collapse of Japan’s economic “bubble” made arranged coupling superfluous.

“[Japanese] society is not as eager to get you married any more,” Ueda says. “It’s increasingly your own responsibility to fend for yourself in the mating market.”

Japan is famously communal; wa, group harmony, is prioritised. Standing out by fending for yourself can be risky business – like posting unpopular words or pictures on Twitter and Instagram. Public physical displays of affection have long been frowned upon. (No one in my Japanese family has ever hugged me.) Handholding happens, but isn’t commonplace. Dating back to Japan’s first contact with westerners, the handshake remains an alien form of greeting: unhygienic, weird, reserved for foreigners. Bow and keep your distance. Even saying “I love you” in Japanese (aishiteru) is virtually verboten, uttered mainly as a joke (safest to say suki: “I like you … a lot”).

All of which may still make Japan the perfect storm of our sexless futures, where physical contact and face-to-face intimacy are fluttering to the ground like so many cherry petals.

• Roland Kelts is a Japanese-American writer and author of Japanamerica: How Japanese Pop Culture has Invaded the US. He lives in Tokyo