(EJ Salisbury is a Back Page Lead correspondent who divides his time between Tokyo, Beijing and Abu Dhabi.)

The ancient sport of sumo wrestling is in trouble. Just like its birthplace, Japan.

These days the most common word used in the same sentence as the name ‘Japan' is ‘disappointment.'

The country has given us so much in the past four decades. Its cars are superior to any other. Its pioneering consumer electronics industry gave us cheap but reliable transistor radios, cameras, video players, and the first personal music player in the Sony Walkman. Japan's industrial companies have changed our lives for the better, and Japanese cuisine has changed the face of restaurants all over the world and vastly improved our quality of life.

Yet these days Japan's economy is still stagnant, nearly twenty years after the bursting of its asset price bubble. Sony is struggling to survive against Korean and Chinese competition. Toyota is in disgrace. And Japanese fishermen will likely be held to blame for the extinction of the bluefin tuna. Whaling in the Antarctic? Why do they continue with the fig leaf of scientific research?

And sumo - a combination of great strength, ineffable grace, and the occasional moment of explosive agility - is suffering a long crisis of confidence. These days it's hard to find a Japanese good enough or even willing to become a yokozuna or grand champion. Though their numbers are limited by the rules, it's the foreign wrestlers who are dominating. Japan just isn't hungry enough to produce many champions any more.

Sumo wrestling tournaments are thought to have begun in 1684. The original sumo wrestlers were samurai, many of them leaderless and without income.

These days a tournament is held every two months throughout the year, each one lasting fifteen days. Bouts begin around lunchtime with the lowest ranking contenders starting off, and the most senior champions finishing off the day's contests just before 6pm. Spectators sit either in tiered rows of seats around the perimeter of the indoor stadium - the raised clay fighting ring in the centre - or on cushions on the floor close to the ring. It's a tradition that the spectators eat and drink while watching the bouts for a few hours.

Until the 1960s all sumo wrestlers were Japanese. The sport has deep links with Shinto religious traditions. For example, before each bout a wrestler will take a handful of salt and cast it out over the floor of the ring to purify the ground and banish ill fortune such as injuries. The notion of a non-Japanese performing these rituals must have seemed outlandish.

Yet in 1964 a sumo stable master invited a well built young Hawaiian named Jesse Kuhualua to come to Japan to train. Taking the fighting name Takamiyama, young Jesse was a success. He grew sideburns, fought well, and displayed a grace and humility the Japanese fans loved. He was the first foreigner to win a tournament and survived twenty years as a wrestler before retiring to become the only foreign stablemaster in sumo history.

Takamiyama was followed by a young man from American Samoa called Saleva Atisanoe, who took the fighting name Konishiki. Though Jesse Takamiyama was big, Konishiki was a monster. Even as a young man he was well over 150kg. By the end of his career, in which he rose to the second highest rank of ozeki , Konishiki weighed 287kg. His girth was so big he could barely use his arms, and the great rolls of fat around his legs shook and wobbled as he walked. It was very difficult for his opponents to move him such was the mountain he represented, and when he won a bout it was often by landing a mighty push square on to his opponents' chests, sending them flying backwards out of the ring.

When he lost it was because an opponent would leap to one side and trip Konishiki, or by grabbing his belt and somehow tugging him off balance, sending the stupendous blubber mountain crashing to the clay. Occasionally a felled Konishiki would roll off the raised ring into the first row of spectators, truly a frightening sight.

After years of good form including winning a tournament Konishiki nearly made it to the highest rank of yokozuna, but private doubts about his temperament - and doubtless a tad of resentment at the success of a foreigner - denied him this prize. Many thought it unfair of the Japan Sumo Association. But Konishiki persevered for a few more years, earning the admiration of many fans for his fighting spirit in the face of injury after injury. Eventually he retired and launched a television and musical career. Other Pacific Islanders followed Takamiyama and Konishiki, one of whom made it to yokozuna.

One of the highlights of Konishiki's career for non-Japanese fans was his appearance as luncheon guest speaker at the Tokyo Foreign Correspondents Club in 1989. Speaking in English, Konishiki gave a fascinating account of life inside a sumo stable. A couple of noteworthy anecdotes are worth retelling.

First, when you enter a sumo stable as a trainee you are expected to do little else than serve the older wrestlers. You are allowed to say only " Thank you," for the first few weeks. An older wrestler decided to test Konishiki's character and casually smashed a beer bottle over his head. "Thank you," Konishiki immediately replied and cleaned up the mess.

Second, many of the older wrestlers are physically enormous. Certainly Konishiki outdid them all in this respect. But being so large they are unable to apply toilet paper to their rear ends after evacuating their bowels following the enormous meals they eat thrice each day. Thus one of the daily tasks of the trainee wrestlers is to take a long handled soft-bristled brush, a bucket of soapy water, and do the job for them. Such is the way to learn proper humility.

Ill treatment of sumo trainees is not always so quaint, though. In 2007 a trainee died after being struck with a beer bottle. The stable master and several senior wrestlers were arrested over the incident.

But the sport reached its public relations nadir with the advent of one Asashoryu, a Mongolian wrestler who began life in Japanese sumo in 1999. By 2003 he was a yokozuna, and in 2005 he became the first wrestler to win all six tournaments in one year, the most successful yokozuna ever.

Pity then that his character was so flawed and his behaviour so awful. Among Asashoryu's disgraces were: alleged match-fixing, assaulting members of the public, insulting his stablemaster, disqualification from a bout for hair-pulling (the first yokozuna ever disqualified), being drunk in public, damaging the cars of opponents, and suspension for lying about his injuries. The last offence was particularly humiliating for sumo - while back in Mongolia allegedly recuperating from an injury and skipping a tournament, Asashoryu was seen on television vigorously participating in a soccer match in Ulaan Bator. Such open contempt for the authority of sumo's governing body resulted in his suspension, again unprecedented for a holder of the sport's highest rank.

Fortunately Asashoryu retired from sumo in February this year.

Fortunately too not all foreign wrestlers are a problem. An Estonian lad named Kaido Hoovelson, a cattle farmer's son used to hard physical work as a child, entered sumo in 2004 and has just been promoted to the second highest rank of ozeki under the fighting name of Baruto (Balt - get it?). A former judo champion of Estonia, Baruto is popular with both fellow wrestlers and sumo fans for his cheerful nature. Win or lose, the Estonian always smiles. On his record so far he may well become the next yokozuna.

In the 1990s it was a Brazilian, one Carlos Ghosn, who rescued Nissan from oblivion. Maybe an Estonian will rescue sumo from disgrace.