A Japanese judo athlete competes against his French opponent at the World Judo Championships on June 13 in Budapest, Hungary. Photo: VCG

It's practiced by tens of millions around the world but there's no doubt that judo's spiritual home is Japan, where the martial art was created and made its Olympic debut.

It will be among the sports most closely watched by home fans at the pandemic-delayed Tokyo Games, and is so deeply embedded in Japanese society it even has its own branch of medicine.

Japan dominate judo at the Games, having won 39 gold medals since it debuted at Tokyo 1964, more than the next four best countries combined.

That's perhaps no surprise given judo's roots in Japan, where it was founded in 1882 by the revered Jigoro Kano, whose benevolent portrait gazes down on judoka at dojos around the world.

Born to a sake-brewing clan from the Kobe region, Kano combined different forms of jujitsu with his own ideas, including spiritual discipline, and believed judo's ultimate goal was to "strive for personal perfection" through discipline and training.

He named his martial art "judo" meaning "the gentle way," and saw it as a means to develop both body and mind. A teacher by trade, Kano was passionate about sport in general, and led the push for Japan to make its first Olympic appearance at Stockholm in 1912.

But judo didn't feature at the Games until Tokyo first hosted the Olympics in 1964.

In competition, judo is contested on a mat with the goal of scoring an "ippon" or full point, which ends a bout.

Ways to achieve this include pinning an opponent for 20 seconds or throwing them so they land on their back. Half-points called waza-ari can also be earned and add up.

Bouts at the Games will last four minutes, and the action is often fast-paced and highly physical.

Hifumi Abe and Shohei Ono are hotly tipped in the men's competition while Japan also has women's stars in Uta Abe and Akira Sone.

'It needs to be fun'

An egalitarian spirit is viewed by some as a key part of judo. 

Winter training at judo's hallowed Kodokan centre in Tokyo is open to ­everyone, and women have practiced the sport since it was founded.

Indeed Kano told his early disciples that the more subtle form of the martial art practiced by women at the time would be judo's "real legacy."

Competition in Japan only opened to women from 1978, however, and female judokas made their first fully fledged Olympic appearance in Barcelona in 1992.

The Kodokan is the sport's home, and in pre-pandemic times attracted enthusiasts from around the world.

It will serve as a training center during the Games, with competition taking place at the famed Nippon Budokan, which has hosted everything from judo to concerts by The Beatles.

"It is not just a Japanese sport," an official from the Kokodan said. "Judo has blossomed as a global culture."

But some worry the martial art is losing its shine in its birthplace, including judoka Tadahiro Nomura, the only person ever to win three gold medals in judo.

"It's something that people [in Japan] just see as an Olympic event," he said. "As for how it's run, how it started, how it spread around the world, the essence of judo, what it can teach kids and so on - all that has been kind of forgotten."

Kodokan officials said they are hoping that "superb performances and conduct" by judoka from around the world "will inspire children to feel that they too want to learn judo."

And Nomura thinks the Olympic spotlight could give the sport renewed vigor. But he worries that dojos are closing and the sport is seen as increasingly inaccessible.

"It needs to be fun, or somewhere to learn etiquette, or something to do for your health," he said.