Japan's traditional costume, the kimono, is rarely worn in contemporary Japanese life except for formal occasions such as weddings. But the yukata, a casual summer robe, is very much in vogue these days, especially among the last group you would expect - fashion-conscious younger people. Yukata-clad young pleasure-seekers can be seen all over Tokyo this summer, and not just at the community festivals in shrines and parks where you might expect them. They are also bringing welcome flashes of colour and style to modern theatres and restaurants.

Yukata were originally home wear - essentially bathrobes - for relaxing in after a hot bath. They are simple but strikingly elegant, made of crisp light cotton and coming in an enormous range of print designs - from eye-popping modern colours to sedate greys and blues. They are worn with the simplest of sashes, unlike the elaborate silk kimono belts, or obi, that require a small posse of helpers to subdue and tie.

Yukata first broke out of the home about 20 years ago, when some designers began to use bold colours and modern prints, often geometrical or floral in the western style. But this was still not mainstream style: at 60,000 yen ($4,100) to 80,000 yen, they were beyond the range of most consumers. But today's yukata can be had for about 4,000 yen, which partly triggered the boom. Two years ago Uniqlo, a popular casual-wear maker, slapped that price on yukata made in China and other parts of Asia, and the fashion began to take off. Other apparel makers rushed into the market as more and more young people snapped them up, along with traditional wooden sandals, hair pins and ribbons.