There was an extra frisson in the air on the first day of the Autumn Grand Sumo tournament in Tokyo. The familiar sights were in place: people streaming towards the stadium, singers belting out sumo songs in Ryogoku station, the hardcore fans gathered at the entrance waiting to greet their favourite wrestlers emerging from taxis and people carriers in colourful cotton kimonos and immaculately waxed topknots, leaving a trail of fragrant hair oil in their wake. Inside, the sell-out crowd was settling in for the afternoon. The lucky ones in the expensive seats were already being tended to by the staff of the tea houses whose job it is to ply them with food and drink. In the centre of it all, the dohyo, the compressed clay ring where the junior wrestlers had been competing since morning. The fans were more expectant than usual. After a year fraught with scandals, expulsions and resignations, Japan’s national sport is in crisis. The chairman of the Japan Sumo Association had resigned only days earlier after two Russian-born sumo wrestlers, brothers Roho and Hakurozan, had tested positive for marijuana. When Musashigawa, the new chairman of the association, stepped up to the dohyo to make the traditional opening address, the tension almost crackled in the air. Flanked by an impressive cohort of wrestlers from sumo’s top division, he cut straight to the point and – to hearty applause – apologised to the fans, promising a new, more disciplined era.

“We have to let out the ills of sumo,” he told reporters. It was a significant moment after a period when the ancient sport has lurched from one drama to the next, with reports of bullying, match fixing (heavily denied) and drug-taking. Add in the shortage of home-grown talent and the increasing dominance of non-Japanese wrestlers in the upper ranks and critics have been questioning sumo’s status as a bastion of Japanese values. “The sport is in worse shape than I’ve ever seen it,” says veteran journalist Kiyoshi Nakazawa, who has been covering sumo for 50 years. Even the government weighed in, with chief cabinet secretary, Nobutaka Machimura, saying that sumo wrestlers should remember “that they are heroes to be admired” and calling on the notoriously exclusive association to change its rules to allow outsiders – and not only former wrestlers – on to its governing body.

The reason it arouses such passion, is that – as aficionados love to tell you – sumo is more than a sport. Legend has it that the very origins of Japan depended on the outcome of a sumo match. The archipelago was ceded to the Japanese when their leader, the god Takemikazuchi, out-wrestled the leader of a rival people. The first matches were Shinto rituals dedicated to the gods and the sport flourished under imperial patronage. Sumo’s connection with Shinto, Japan’s indigenous religion, is still an integral part of the sport. The roof that hangs over the dohyo resembles a Shinto shrine; the black gauze hats worn by the referees are modelled after those of Shinto priests. And when a high-ranking wrestler steps into the ring (which, incidentally, no woman is permitted to do), he purifies it symbolically by throwing salt in the air.

Arcane cultural elements are part of sumo’s appeal. The referees wear lavish kimonos styled after those worn by Samurai; the ushers still wear Edo-era workmen’s outfits. The wrestlers make a brief appearance in their embroidered ceremonial aprons, but for the bouts wear a simple mawashi, a length of folded silk 9m long, with their hair coaxed into a special tournament style, designed to resemble the leaf of a gingko tree. History and pageantry, however, are never allowed to get in the way of what is essentially a thrilling spectator sport.

Today there are 53 stables – all run by ex-sumo wrestlers – with 720 wrestlers, 59 of them non-Japanese. It is a cloistered, stratified society in which everyone from hairdressers to the referees is slotted into the pecking order. The wrestlers are ranked by ability, and nothing happens in training, competition or daily life without reference to this hierarchy. There are strict codes of conduct for all wrestlers and none more so than for the grand champions (yokozuna), who are expected to be models of good behaviour.

A wrestler’s daily routine is a repetitive regimen: training, eating, sleeping all afternoon, then more training. The wrestlers sleep in a shared room; they train, cook and eat together. They eat large quantities of chanko-nabe – meat or seafood stew – to bulk up. Only when he reaches a certain rank (or gets married) can a wrestler have his own room or live outside the stable. In Tokyo the stables are dotted around the area near the Kokugikan sumo stadium in Ryogoku. They look no different from the buildings around them, apart from the odd journalist or photographer waiting outside and the grunts and thuds of a practice session coming through an open window.

The rigours of the training sessions quickly dispel the idea that sumo wrestlers are all blubber. Up close you can see the hard graft that goes into building up the strength and flexibility required to be a top wrestler. Every stable has its own dohyo and hours of practice are part of the daily routine. The stable master and manager sit at the side watching, only occasionally telling their charges to push harder or squat lower. The junior wrestlers take it in turns to go up against the higher-ranked wrestlers and are bulldozed around the ring. They all look shattered at the end of a session.

At Takasago stable, there is a new recruit, a skinny 20-year-old. Only 65kg, he is thrown around like a rag doll, gasping for air as he is repeatedly flung against the floor. Yet he never once complains, in spite of the bruises and badly scuffed shoulders. He then has to help cook lunch for the other wrestlers and, naturally, eats last. “What we look for most in a young wrestler is his fighting spirit,” says Suehiro Nagaoka, the Takasago stable-master. “They can always put on weight.” For those in the lower ranks, it is a Spartan, regimented life (one that was highlighted last year when a 17-year-old wrestler died after a beating by fellow wrestlers, apparently at the behest of his stable master). You do, however, get the sense that the best-run stables are like surrogate families, with the oyakata (stable masters) taking on a paternal role.

The financial rewards for a junior are hardly enticing. There’s a fixed salary system and only those at or above juryo level (second highest) receive a wage from the association. In other words, only a tenth of sumo wrestlers are being paid. The rest get food and lodging but otherwise rely on the meagre fees they receive for tournaments and the patronage of salaried wrestlers in their stable. The highest rank yokozuna gets a basic salary of ¥2.8m (€18,000) a month, plus tournament fees, tours abroad and rewards from sponsors. But for all its hardships at the lower levels, there’s a glamour to being a wrestler that sets them apart, making them at once celebrities and cultural icons.

“Not many young Japanese have the patience or endurance for this life now,” says Takaju Hinahata, the hairdresser at Takasago stable. “It’s not just sumo that’s changing – society is changing.” All the old-hands agree that wrestlers from Mongolia and Eastern Europe have a hunger that is sometimes lacking from their Japanese counterparts. Newcomers such as Kotooshu, the 2m- tall Bulgarian, and Baruto, the bulky Estonian 24-year-old, have risen to sumo’s senior ranks and are popular with fans. Usually scouted through contacts in the wrestling world, they’re expected to fit in with the language and the customs, including wearing their hair in the traditional top knot (not easy for some folically challenged Caucasians). It’s a sign of the times that the two current grand champions are both Mongolians, who go by the Japanese fighting names of Hakuho (White Phoenix) and Asashoryu (Blue Dragon of the Morning).

“Being a yokozuna is a huge pressure,” says Hakuho in fluent Japanese. “I’m an ambassador for the sport and I always have to behave in a certain way.” It is the one rank from which there can be no demotion. Once a wrestler is promoted to yokozuna the only way out is retirement. “Every loss is much heavier at this level,” he says. Still only 23, he rose to the top rank in July 2007. He came to Japan as an adolescent wrestling hopeful aged 15, when he was only 176cm tall and weighed less than 65kg. His father had won a wrestling medal for Mongolia at the 1968 Olympics. “Wrestling is in my DNA,” he laughs. No sumo stable spotted his potential and he was about to head back home when the master at the small Miyagino stable suggested he stay on – eat, sleep and train.

“It was a hard time for me,” he says. “I didn’t speak any Japanese and I had to learn to fit into this hierarchical world.” Within three months his weight had gone up and he was on his way to becoming the hulk he is today. In the dohyo he is a fearsome presence, now 193cm tall and weighing 153kg. In person he is charming – polite and thoughtful. He takes his position as a role model seriously, trains hard and works with the junior wrestlers, who consider it an honour to take him on in a training bout (“He’s like a god to us,” says one young wrestler from his stable). Sumo followers say he has all the makings of a classic yokozuna. “Of course, the fans would love to see a Japanese yokozuna,” he says. “But when they see that you’re making an effort, they support you.”

The other grand champion is Asahoryu, 28, who is sumo’s bad boy, a physically gifted maverick. Stocky and fast (185cm, 148kg), his record is one of the best in sumo history and he was the first Mongolian to reach the rank of yokozuna. He’s also the winner of 22 tournaments and the first wrestler to win all six grand tournaments in a calendar year. From 2003 to 2007 he was the only yokozuna in sumo. Yet for all his success, there has been a persistent question mark over his attitude – the general consensus being that he doesn’t behave like a grand champion.

Charismatic and outspoken, Asahoryu has been involved in numerous controversies, from yanking an opponent’s top knot – considered very unsporting – to calling on the Sumo Association to give the wrestlers a pay rise. Last year he was given a two-tournament suspension and a 30 per cent pay cut when he missed a regional tour, citing injury, and then played in a charity football match in Mongolia. After a pasting in the Japanese press and a leave of absence, he returned to make a public apology. Detractors complain that he is wreaking havoc with the dignity of the sport, but many fans admire his technical prowess. After so long in the spotlight, he admits he is weary of the attention, and retirement – probably in the next couple of years – and Mongolia beckon. “I’m tired of the press,” he says. Chatting after a practice session, he whips out his mobile phone to show pictures of Mongolia and his meeting with the Dalai Lama in Kyushu in 2005. Drama seems to follow him wherever he goes. “I was a naughty child, too – I think it was my destiny.”

Sumo has been through tough times recently but with new leadership at the association, many are hopeful that this will be a fresh start for the sport. “We need to make sure that the wrestlers get back to the basics – training, eating chanko and sleeping,” says Nakazawa, who airs his views on the need for reform in the sumo monthly, Ozumo. “I’ve been writing my column for 20 years and I’ll write it for 20 more if I have to,” he says. “I love the sport – I want it to last.”

To see more on our sumo Expo visit monocle.com and watch our slideshow of life in the stables.