The lights dim provocatively. Duran Duran's 1980s song Wild Boys pumps deafeningly from the speakers. With tension so real you can touch it the pouting models strut on to the catwalk — wearing nappies.

In a country where the ageing population is growing more quickly than almost anywhere else on Earth, this disturbing extravaganza — a parade of cutting-edge adult nappy technology displayed by models wearing black catsuits — may shape future fashion shows in Japan.

Extremely long lives and a rapidly burgeoning elderly population in Japan have created a lucrative “silver” services industry to keep the greying ranks healthy, entertained and, in the case of the £550 million-a-year adult nappy business, dry and confident.

As designs from the 2008 autumn collection were paraded across the stage to the strains of Frankie Goes to Hollywood, the Pretenders and Tears for Fears, the rapt audience goggled at a bewildering array of choice.

Larger companies such as Livedo and Unicharm offered dozens of different shapes and sizes; others competed to offer a more exclusive nappy couture.

Could anything match, for example, the sheer elegance of the Nishiki 100cc knit-trunk safety briefs, or rival the robust simplicity of the Pigeon easy-fit haku-pants? Would customers prefer the discretion of a nappy disguised as regular cotton boxer shorts, or opt for the bulkier, more absorbent man-made fibres?

The models — men and women of a mixture of ages — were recruited by several awareness groups that organised the show, including the Ageing Lifestyle Research Centre and the Excretory Institute of Japan in Kyoto.

The event was planned because even though the inconveniences of old age are a reality for millions of Japanese people, adult nappies remain a taboo subject, one of the organisers told The Times.

For the sake of the growing number of elderly and for the increasingly strained care and nursing industry, making adult nappies mainstream is viewed as a key to ensuring that people remain active longer.

In Japan, 22 per cent of the population are aged over 65 and by 2050 it is expected that there will be more than a million centenarians.

“We must think of adult nappies as a tool of freedom in old age — just like reading glasses,” said Sachiko Hanari, an expert on elderly care, in a presentation to the 1,000-strong audience.

Her demonstration was followed by several sketches aimed at highlighting the importance of selecting the right nappy and a generous offer to would-be nappy fitters — a course that provides the applicant with a nappy consultancy licence for 20,000 yen (£100).

The fashion show was arranged “to replace the public perception of nappies as something embarrassing and filthy with something cheerful and humorous”, Kiyoko Hamada, of the Ageing Lifestyle Centre, said.

The event, she added, was not an attempt to cajole people into wearing something that they felt they did not need, but to provide information on a technology that has advanced farther than many people could imagine.

Disposable fortune

— In 1947 George M. Schroder invented the first non-woven fabric “diaper”, the precursor to the disposable nappy, in Texas

— The disposable nappy industry is worth $5.7 billion (£3 billion) a year

— Astronauts wear nappies called maximum absorbency garments, or MAGs, during lift-off and landing. On space shuttle missions each crew member receives three nappies - for launch, re-entry and a spare

— The Real Diaper Association estimates that 27.4 billion disposable nappies are used each year in the US and they become 3.4 million tonnes of waste, which is dumped in landfills

Sources: Nasa, Texas Legacy Project, Time

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