THE JAPANESE are masters at the art of convenience living. This is, after all, a country in which practically every street corner is furnished with a vending machine selling anything from the energising if unfortunately named soft drink, Pocari Sweat, to chilled green tea and hot coffee. And, quite apart from the ubiquitous noodle restaurants, several fast food chains have for years served indigenous eat-and-go meals. Among these, Tenya operates principally in the environs of Tokyo. It offers tendon, an inexpensive version of tempura delivered on a bed of rice and accompanied by bowls of miso soup. Yoshinoya, (pictured above), is a rather larger company with more than 1,000 outlets across Japan and around 250 overseas (in New York, Taiwan, China and more). It does brisk business in gyudon, bowls of rice topped with slightly sweetened beef stew.

The popularity of such home food has not, of course, precluded the arrival and rapid spread of Western-style chains: Kentucky Fried Chicken, the Korean hamburger group Lotteria, Mr Donut, Wendy's and, inevitably, McDonald's. The first of these opened in Japan in 1971 and has since spawned around 3,760 outlets nationwide.

It was about a year after McDonald's was introduced that Mos Burger appeared, a Japanese answer to the global giant - even its M logo looks remarkably similar to that of its mighty American counterpart. Yet Mos Burger is no mere imitator and has put an enterprising spin on the hamburger concept. Underlining the company's ethos to produce healthy, tasty food, Mos is an acronym for mountain, ocean and sun. It implies a breath-of-fresh-air approach to burger-style fare. And although Mos Burger's menu does offer conventional hamburgers it also features wholesome options in which the burger bun is replaced by lettuce leaves that act as wrappers or by warm and sticky rice cakes. A minced prawn burger in a rice cake sandwich, for example, costs Y700 (pounds 3.60), while a chicken burger with salad is a shade cheaper at Y670 (pounds 3.45). Drinks and desserts have a very Japanese flavour: the likes of green tea with sweet beans and chestnuts and green tea ice-cream shake. Meals are made to order, a slight sacrifice of time for a fresher, tastier product, they say. So which is more popular, McDonald's or Mos Burger? After a short pause, one Tokyo resident simply told me that "McDonald's is cheaper".