By Philippa Fogarty
Mongolian Asashoryu is known as the bad boy of sumo
Right now, all eyes in Japan are on the leadership crisis playing out in central Tokyo's Nagatacho district.
But only a few miles north-east from where the next prime minister will be chosen, another crisis is rumbling.
At the sumo stadium in the Ryogoku district, the autumn tournament is in its second week. But the sport's top fighter - and one of its leading draws - is not there.
Mongolian-born grand champion Asashoryu has returned to his native land, apparently suffering from deep depression triggered by a suspension.
And it appears that Japan's sumo elders are not sure whether he will return, or indeed if they want him back.
Asashoryu - or Dolgorsuren Dagvadorj - is one of the most successful sumo wrestlers ever.
He made his professional debut in 1999 and rose rapidly through the sport's ranks, achieving top-level yokozuna, or grand champion, status four years later.
WHAT IS SUMO?
Sumo is Japan's national sport, dating back hundreds of years
Two wrestlers face off in an elevated circular ring
They try to push each other to the ground or out of the ring
Wrestlers are ranked, and the highest level is yokozuna
There are only two yokozuna, Asashoryu and Hakuho
Since then he has won 19 tournaments, and for more than three years was the sport's only yokozuna.
But the 26-year-old is also known as sumo's bad boy, and has drawn criticism from the sumo community, which is governed by hierarchy, ancient rituals and a strict code of conduct.
In 2003 he was disqualified for tugging on an opponent's top-knot - something banned in the sport. On another occasion he argued with judges after a decision went against him.
He has also been criticised for injuring a fellow wrestler in training and for appearing in public in a suit, rather than a Japanese-style outfit.
Most seriously, he has been accused of failing to adopt the humble and dignified attitude expected of a yokozuna, and to act as a good role model for the sport.
The final straw came in July. Asashoryu told the Japan Sumo Association (JSA) that he was injured and could not participate in a regional training tournament.
But he was then seen on television enthusiastically taking part in a charity football match in Mongolia, alongside former Japanese football star Hidetoshi Nakata.
The JSA reacted swiftly, banning him for two tournaments and slashing his pay. It was the first time in the history of the sport that a yokozuna had been suspended.
Asashoryu responded to the punishment by spiralling into depression. As media coverage of the row escalated, he refused to appear in public, remaining shut inside his house.
At the end of August, the JSA finally conceded to advice from doctors that he should return to Mongolia to recuperate.
There, where Asashoryu is a national hero, there was no doubt that he had been harshly treated.
"People think the decision to suspend Asashoryu is a very strong one," says Indra Borkhondoin, editor in chief of the English-language Mongol Messenger. "It has been big news in Mongolia."
But in Japan, there are mixed feelings.
Part of the problem, says sports promoter Jack Sakazaki, is that in Japan sumo is more than just a sport.
"Some of the foreign wrestlers get strong quickly, but it is not just about being strong," he says. "Sumo is Japan's national sport and it symbolises the samurai spirit, so it involves many different things."
Foreign wrestlers like Bulgarian Kotooshu are taking up sumo
"You can't allow one person special privileges. The JSA has taken a proper step, because if not, the others would start thinking they could behave like this."
Jack Gallagher, sports editor of The Japan Times, says the main issue is that Asashoryu has ruffled a lot of feathers within sumo.
"It's a very staid culture and they don't take kindly to people who fail to conform," he says. "He is up against the fact that he is not Japanese, but in the sumo world he is expected to behave like he is."
But Asashoryu is not the first foreign wrestler to penetrate sumo's upper echelons.
Hawaiians Akebono and Musashimaru both reached the sport's top rank in the 1990s, while Hakuho, another Mongolian, joined Asashoryu as a yokozuna in May. There are dozens of other wrestlers - from Bulgaria, Russia and China - lower down the sport's rankings.
Mr Gallagher points out that other foreign wrestlers have not had the same problems as Asashoryu.
But he says that there are two schools of thought. "One is that Asashoryu got what he deserved, the other is that it was a big over-reaction on the part of the JSA."
Japan's sumo elders may well face similar issues in the future.
Fewer and fewer Japanese men are joining the sport, put off by the strict training regime and controlled lifestyle.
"Younger kids would rather make money without work - gain without pain. And sumo is a lot of pain," Mr Sakazaki says.
Wrestlers have to dedicate themselves completely to the sport, he says, and the rewards are not huge for lower-ranked fighters.
So the foreign wrestlers are needed to fill the gaps. They also draw in international fans, something the sport badly needs.
"Sumo is in serious trouble," says Mr Gallagher. "Audiences are declining and sports like soccer are doing their marketing better and taking a larger piece of the pie."
He says the JSA has failed to address these issues. But revitalising a sport based on centuries of tradition is no doubt easier said than done.
"The charm of sumo is that it is what it always has been for the last few hundred years," says Mr Sakazaki.
"You don't want to see sumo wrestlers wearing sweat pants. By changing things, you may deprive the sport of what it has been all these years."
Asashoryu is currently holed up at a hot spring resort southwest of Ulan Bator, his doctor on hand. Earlier this month, his brother denied speculation that he was considering retiring.
Sumo elders have called on him to return. But at least one member of the JSA's Yokozuna Deliberation Council wants him out.
"He abandoned his job of being a public servant and he should take the responsibility and retire," Makiko Uchidate told Kyodo news agency. "As a man, I'd like him to take the high road and graciously bow out."
With sumo likely to become increasingly dependent on foreign wrestlers for its survival, it will be interesting to see if Japan's sumo elders will show any flexibility with their troubled champion.