Next time you're out shopping for a new getup consider the safety factors. Can that $500  designer frock you've been admiring in the David Jones windows ward of criminals? Can it morph into a sheath shielding you from the underworld elements? No? Well maybe you should be turning to Japan's emerging designers for inspiration... and protection.

As reported in the New York Times, Aya Tsukioka has been designing clothes that she hopes will ease Japan's growing fear of crime.

The 29-year-old fashion designer has created a skirt, that with one simple swift motion, can turn into a fake vending machine. In a demonstration held on a small Tokyo street, Tsukioka shows how by holding the skirt upwards and stepping to the side of the road, a woman walking alone could elude pursuers — by disguising herself as a vending machine. The wearer then hides behind the sheet, which is printed with an actual-size photo of a vending machine.

These elaborate defenses come as crime rates are declining in Japan. But the Japanese, attuned to the slightest signs of social fraying, say they feel growing anxiety about safety, fanned by a sensationalist news media.

But instead of pepper spray, the Japanese are devising a variety of novel solutions.

Take the "manhole bag", a purse that can hide your valuables by unfolding to look like a round sewer cover. Put it on the street with your wallet still inside, and unwitting thieves are supposed to walk right by.

There is also a line of knife-proof high school uniforms, and a book with tips for mothers on how to dress even the most modest children like "pseudo-hoodlums" to scare away schoolyard bullies.

There are pastel-coloured mobile phones that parents can track using the global positioning system, and a chip for backpacks that signals when children enter and leave school.

"It is just easier for Japanese to hide," Ms Tsukioka told the New York Times. "Making a scene would be too embarrassing."

She said her idea of the vending machine disguise was inspired by a trick used by Japan's ancient ninja, who cloaked themselves under black blankets at night.

Some of the ideas, including the vending machine disguise, have yet to become commercially viable. But they've been greeted with straight faced enthusiasm by Japanese inventors.

According to inventors, a long tradition of tinkering and building has made Japan a congenial place for experimental ideas, no matter how eccentric.