In this picture taken on February 5, 2018, a man looks at the condoms displayed in a Condomania condom shop at Harajuku district in Tokyo. (AFP/Behrouz Mehri)
Japanese condom makers are ramping up preparations ahead of the Tokyo 2020 Olympic Games, seeing a golden opportunity to showcase their world-record ultra-thin products.
For years, hundreds of thousands of condoms have been distributed for free to competitors at Olympic Games in a bid to encourage safe sex among the world's fittest athletes.
The tradition provides prophylactic producers with a potentially unrivalled marketing opportunity.
In Japan, condom makers are hoping the Olympics will be a chance to introduce customers to what they consider their gold-medal innovation: the ultra-thin 0.01mm condom.
In addition to its barely there construction, the condoms are made of polyurethane, a material suitable for people allergic to the latex that is standard for many condoms.
"It's only Japanese companies that now manufacture condoms as thin as 0.01-0.02mm," said Hiroshi Yamashita, senior manager and spokesman at Sagami Rubber Industries, a leading Japanese condom maker.
"We see (the Tokyo Games) as an extremely precious opportunity to let the world know about Japan's high-technology."
Condoms have long been Japan's most popular contraceptive method, with birth control pills not even available on the local market until 1999.
But Japan's condom makers currently lag behind rivals internationally, with Britain's Durex and US firm Trojan the world's top dogs.
Japanese producer Okamoto Industries is tied for third place with a condom unit formerly owned by Australia's Ansell, while Sagami comes next, according to Yamashita.
In this picture taken on January 25, 2018, employees of Japanese condom maker Sagami Rubber Industries perform quality tests for randomly picked condoms at the company's testing facility in Atsugi, Kanagawa prefecture. (AFP/Behrouz Mehri)
Sagami has been in business since 1934, when its founder Saku Matsukawa started it to help fellow Japanese women prevent unwanted pregnancies at a time when poverty and food shortages haunted the country.
But after decades of popularity, sales in Japan began to drop in the 2000s, partly due to an ageing population and a rising number of young people staying single.
Looking for ways to revive their fortunes, Sagami developed the 0.01mm condom, which hit the local market in 2013, and sales have perked up since, according to Japanese industrial body Condom Kogyokai.
It says Japanese companies produced around 417 million condoms in 2016, the last year for which it has figures.
"Condoms are an effective means to help people protect themselves from contracting sexually transmitted diseases, and the thinner they are, the more men tend to use them," said Tomonori Hayashi, marketing manager at Okamoto, which put its own 0.01mm condom on the market in 2015.
"We expect that our products will be highly valued at the (Tokyo) Olympics," he told AFP.
Japan's 0.01mm condoms were developed in part by Chiaki Yamanaka, an assistant manager at Sagami who is known to colleagues as "Mr Condom," a moniker he laughs off.
"We had lots of debate in the company about whether there would even be demand for 0.01mm condoms when we already had 0.02 mm products on the market," he told AFP.
"But they have proved to be popular with customers," he added, pinching at a virtually invisible condom covering a glass cylinder at a testing facility.
Sagami manufactures its polyurethane condoms in Malaysia but conducts six different tests for product quality.
At a facility near Tokyo, workers in white masks and jackets test the endurance of products by filling them with air and water until they burst.
Nearby, a machine testing resistance to friction produces a low, deeply unromantic, rhythmic hum.
Condoms must be able to resist the friction of at least 100,000 thrusts, the company says. They haven't tested an upper limit beyond that.
Dreaming of Olympic gold
At this year's Pyeongchang Games, organisers handed out a record 110,000 free condoms, and the Tokyo 2020 organising committee told AFP they had no plans to break with the tradition.
"We are planning to provide condoms as one of the amenity items at the athlete's village, although how many and which brands has yet to be decided," a committee official said on condition of anonymity.
Sagami has been dreaming for years of having its products distributed to Olympians in 2020.
"When Tokyo was selected to host the 2020 Olympics, condom distribution at the athlete village immediately came to our minds," Yamashita said.
"The company worked hard to get the 0.01mm products to market well before the Tokyo Olympics."
And with high hopes for an Olympic bonanza, it is ramping up production and opening a new factory in Malaysia to meet growing demand.
In Tokyo's quirky Harajuku district, Koji Negishi looked on proudly as customers browsed through the wide range of condoms available at his boutique, Condomania.
His stock features everything from imported flavoured and textured varieties, to Japan's homegrown ultra-thin rubbers.
He has no doubt that foreign visitors attending the Olympics will fall for Japan's premium condoms.
"Condoms thinner than those overseas are very popular," he told AFP.
"Many visitors from abroad come here and buy (Japanese) products because they are thin and high-quality."