An ancient sport shrouded in mystery, professional sumo wrestling is reserved only for men in Japan. Hiyori wants to change that. 

In Japan, it’s said the sumo ring is the dwelling of the gods. The dohyo, as it's known, is also a space in which women have long been deemed too "impure" to enter.

But 26-year-old Hiyori Kon was born to be a warrior.

The dohyo is her realm – the place where she reigns supreme, where she feels totally herself.

It could also be the scene of her greatest victory or her most crushing defeat.

She wants to win, for the first time, the Sumo World Championships, the biggest tournament in female sumo.

Hiyori is the hometown favourite. The sounds of young boys and girls cheering her name fill the stadium as she steps into the ring for the final bout.

But standing in the way of glory and gold is a larger and more experienced opponent, Ukrainian Ivanna Berezovska.

If Hiyori is feeling the pressure, she's not showing it.

"Never nervous," she says with a smile.

"I'm ready to become a hero."

Sumo may be Japan's most iconic sport, but it's a sport ruled by deep, "male-centric" conservative traditions that leave women with little opportunity.

Unlike Australia, where recent on-field success in AFLW, cricket or soccer has ignited interest in women's sport, women's sumo in Japan remains of "little value".

"I don't think the government and many companies or universities recognise it," Hiyori says.

Hiyori has led a campaign for respect and recognition, garnering national and international media attention.

But years of advocacy, training, competing, and working a full-time day job have left her exhausted. She's taking a long break and this could be her last Sumo World Championship.

For now, her focus is on what's right in front of her.

In a few moments, Hiyori's fists will touch the ground, marking the start of the bout, and she will charge at her opponent.

It's an unforgiving sport.

Victory in the sumo ring, or dohyo, will be determined in seconds.

"When I see my opponent in the dohyo, I can feel how much the person has trained and how confident the person is," she says.

"There are times when I'm afraid of my opponent's power, or when I want to give up the fight and run away, but in those moments I believe in what I've been doing.

"I think about how to win definitely. I repeat it over and over again in detail and visualise it."

Before she even entered the dohyo, Hiyori had to wage many battles — against misogyny, tradition, and economic hardship. 

Every step of Hiyori's young life has led to this moment. 

'The sumo world is in this spiral right now' 

On a cold Saturday afternoon, Hiyori is dedicating her free time to teaching kids at the Ota Arashi Sumo Club.

The boys and girls are in a squat position, as they lift their legs high in the air, before stomping them back on the ground.

It's an iconic sumo move, designed to ward off bad spirits and intimidate your opponent.

It's also a great way to test your balance, and strength, and get the heart pumping.

"If you practise while your body is cold, the risk of injury increases," the coach yells out.

The rules of sumo are simple. Only the soles of your feet are allowed to touch the ground. If you force your opponent to buckle or toss them out of the ring, you win.

"Sumo is really a match of mind, technique, and body in a split second," Hiyori explains.

Sumo participation rates among young people are dropping, and clubs are closing.

Kids these days simply view soccer, baseball and even rugby as cooler, while parents fret over the safety of sumo.

The iconic sumo stables, where wrestlers live and train, are finding it harder and harder to adopt new apprentices.

Last year's intake on the national scale was so low, Japanese media branded it the "worst" recruitment season.

"Any sport needs support and without that support, the number of athletes doesn't grow," Hiyori says.

"On the other hand, when the number of athletes doesn't increase it's difficult to get support.

"I think the sumo world is in this spiral right now and I hope it can get out of that spiral somehow."

But at the Ota Arashi Sumo Club, at least, there's no shortage of enthusiasm, as the young kids closely observe Hiyori's every move.

"My dream is to win the world competition," 10-year-old Kanano Suzuki says.

It's a dream her family wholly supports.

"There was no culture of women doing sumo in Japan," her grandfather, Mitsuaki Suzuki, says.

"Nowadays, with the introduction of gender equality, women also started to do sumo. It's such a wonderful thing."

But sumo is far from achieving gender equality.

Professional sumo is strictly reserved for men only; women are relegated to amateur status. Earning a liveable income from the sport is impossible.

Simply finding a club that can accommodate girls can be challenging.

"Some local clubs refuse to accept female wrestlers," Hiyori says.

"Even if they can do sumo at primary and junior high school, there are only a limited number of high school clubs for boys, and those schools don't usually accept girls.

"The number of universities that accept girls are only a handful."

'Men have a wide range of choices' 

Hiyori has become the leading figure fighting for recognition and respect.

She's the star of a mini-Netflix documentary Little Miss Sumo and was listed in the BBC's Top 100 Women list in 2019.

On the day she's training young kids, a French magazine has stopped by for some photos.

But fame and success do not pay the bills.

Instead, Hiyori works full-time at a car parts company and lives in a small one-bedroom apartment in the industrial city of Kariya.

"I often wish that sumo, as a modern sport for women and men alike, could become a profession or reach a level where people could earn a living," she said.

Hiyori was fortunate to find a workplace that considered sports part of the company ethos.

It sponsors local clubs and encourages staff to get active.

Like many in Japan, it also had its own corporate sumo club. But it was for men only — until Hiyori stepped in.

"Men have a wide range of choices," she says.

"Women really have to go out and look for it on their own.

"I searched for an opportunity by myself, negotiated, and got my position."

Hiyori's work accommodates her tournament schedule, giving her time off to compete in Japan and abroad.

But finding the time to train is up to her.

That means she must hit the gym before sunrise, and then head off for a long day at work. 

It's not only physically exhausting but mentally too.

Japan routinely ranks low on issues relating to gender equality, and the country is renowned for its long working hours.

Hiyori feels mounting pressure to give up her sumo dreams.

"Women feel pressure to give priority to childcare, housework," she says.

"People would say, 'Why is a woman still doing sumo?' [and] 'Do you think about getting married or having a baby?'

"Sometimes I feel like I'm being defeated by these voices."

The sport of the gods 

The story of sumo is woven throughout Japan's ancient history.

According to one mythological tale, the first bout took place on Japan's shoreline, as two gods fought over the country's sovereignty.

In reality, sumo has served a variety of purposes over its 1,500-year history, as entertainment, a form of military training, and as a symbol of nationalism during Japan's days of colonialism.

After the country's defeat in World War II, sumo shed its militaristic identity and emphasised its sporting characteristics.

Even though sumo has evolved, the Sumo Association, which governs professional sumo rather than amateur competitions, emphasises tradition as a core component.

At the start of each tournament, the dohyo is blessed. A god is said to occupy the space until the sumo ring is destroyed after.

Women are prohibited from stepping foot inside the dohyo due to an archaic argument that menstrual cycles make them "impure".

Women are therefore prohibited from competing in the same space as the professional men.

But the rule impacts women in other ways.

A female mayor was once prohibited from handing out medals during an award ceremony.

Wives of sumo can't join their husbands for important milestones, like getting the topknot cut off at the start of retirement.

In 2018, the rule was even enforced during a matter of life and death. After a mayor collapsed inside the sumo ring, women who had rushed to his aid, including one doing chest compressions, were ordered out of the ring.

The Sumo Association released a statement later stating that emergencies were the "exception" to the rule.

Masataka Suzuki, a professor emeritus of cultural anthropology at Keio University has written a book about female sumo.

He says the rule is outdated, and tradition needs to undergo changes to suit contemporary thinking.

"The idea of defilement violates women's human rights," he says. 

For hundreds of years, women weren't allowed to climb sacred mountains across Japan. The Mountains of Dewa, for instance, only opened up to women in 1997.

Just this year, women were allowed for the first time to participate in an 800-year-old fire festival in western Japan.

But Professor Suzuki says the Sumo Association showed no interest in changing the rule.

And it has shown no interest in supporting women's sumo.

"The Sumo Association is an extremely male-centred society," he says. 

"There is no perspective on women, no atmosphere of tolerance for women.

"It needs reflective thinking."

The women who want to save sumo

In 2001, women's sumo went global when it was finally included in the World Sumo Championship, almost a decade after the annual event was set up for men. 

At the time, there was speculation sumo would become an Olympic sport if the Japanese city of Osaka was successful in its bid to host the 2008 games.

If that happened, sumo needed male and female competitors.

It was enough to convince Emi Kakizoe, who was in high school at the time, to give it a crack.

"The number of athletes were really small," she recalls.

"I was the first one to compete in the heavyweight division and there were only four of us."

Emi was a pioneer of the sport, continuing to compete throughout university.

But she experienced a nasty reception.

"I was told that I was a pioneer," she said.

"But people would say it sarcastically like 'because you're fat'.

"When I participated in games, my schoolteacher said to me that I was immodest and, 'Why would a girl do such a thing?'" 

Her competition days came to an end and sumo never became an Olympics sport, despite the capital Tokyo hosting the games in 2021.

Australian sumo commentator, Murray Johnson, says it was a missed opportunity.

"I think sumo would be a pretty exciting sport at Olympic level," he says. 

"If you saw women in sumo at the Olympic level, that would absolutely help make it grow on an international level. It could only be good for the sport."

Its exclusion was a puzzling decision for competitors, considering the International Olympic Committee finally recognised the sport only a few years prior.

Murray levels much of the blame at the Sumo Association.

"They're totally disorganised as an international body," he says.

He says it's an organisation stacked with conservative thinkers, who, if anything, have turned the sport more inward, with a focus on tradition, men, and Japan.

"They don't want to lose their identity because it is a Japanese sport, once called the national sport," he says.

After an influx of impressive wrestlers from places like Mongolia and Hawaii, the Sumo Association capped the number of foreigners allowed.

In 2002, it imposed further rules on sumo stables, restricting them to only one foreign wrestler each.

"What the Sumo Association doesn't like and some sumo organisations don't like is the concept of it being like wrestling — double back flips when you win and high fives and all that sort of thing. They can't stand that," he says.

"I think it will eventually change, but I don't think I'll be alive."

But there are some fresh thinkers emerging.

For the past year, Emi has been running a sumo stable, Ikazuchi Stable, with her husband and stable master, Toru Kakizoe, to train the next generation of champions. 

While their training regimen remains tough, the pair has adopted a kinder approach to their sumo, especially to their star Ukrainian recruit, ShiShi, who suffered severe homesickness.

"The environment is totally different from when we were sumo wrestlers 20 years ago," Emi says.

"The wrestlers themselves want to be accepted as a family and not to be in just a strict place."

She also looks at the current crop of female sumo in awe.

"I'm most happy that sumo has become a sport that people don't feel embarrassed about," she says.

"It's interesting to think that my daughter might be standing in the ring in the future, and I really want to support them."

'Some people looked down on me for being a girl' 

Some old institutions are changing.

Keio University is one of Japan's most prestigious. Its sumo club is over a century old, and during that time, it's never had a female wrestler. Until now.

Rio Hasegawa, 20, is a rising star of sumo.

"In the past, some people looked down on me for being a girl, but here, I don't get that kind of thing at all," she says.

"I'm going to train with this team in my own way. No-one tries to be in my way or drag me down."

Rio comes from the northern prefecture of Aomori, a region famed for its natural beauty and apple orchids.

"The kind of countryside you would expect to see in a Ghibli [anime] movie," she explains.

It's also known for producing the greatest number of professional sumo.

Her late father, like many in the community, was a devout sumo fan, and she trained with her brothers at a local club. 

"I didn't grow up with much praise," she says. 

"My father was the type of person who would tell me to do your best and not be satisfied at where you are, rather than tell me that I had done a great job.

"Sumo became something I had to do, and I had pressure to win matches."

But now living in Tokyo, she's charting her own path, and has discovered a renewed love for sumo.

She dyed her hair a vibrant red, a break from the traditional sumo black, for no other reason than it looked cool.

She wants to win the biggest tournaments but also prioritises studying.

A career in sumo for women in Japan is, after all, impossible.

"I was a person who gave up on things because of sumo," she explains.

"So, I thought, I don't want to give up on my hobbies or fashion, and I want to enjoy being careful about my appearance. If there are children who are giving up something because of sumo, I feel that they don't have to give it up."

Her club coach Fumihiko Nara is a member of the Sumo Federation, which manages amateur sumo. He believes the sport needs to evolve.

"Many reforms are needed," he says.

"I would like to see [sumo] being more open and allow people from various countries to join … [It must] increase the number of female participants and the number of female athletes worldwide."

He believes Rio can usher sumo into a new era.

"Rio has opened the door for the next generation," he says. 

"She will be a person who would introduce women's sumo, and amateur sumo, to the world."

The battle of the female warriors 

At the Sumo World Championships, Hiyori makes light work of her opponents from the United States and Poland.

But it's Ukrainian opponent Ivanna that worries her the most.

In Ukraine, top female wrestlers can get government support, including money for flights and a monthly wage.

It gives athletes like Ivanna more time to train and compete.

Hiyori doesn't have the same opportunity. 

And so when she steps into the dohyo and faces off against Ivanna, she must rely on her body, her indomitable spirit, and a little bit of luck. 

The bout begins.

The two heavyweight sumo clash.