When you think of sumo outside Japan, the image that often pops up is a comical scene of hefty men in mawashi (the traditional belt) bumping into each other like oversized toddlers. Yet, behind that cartoonish façade lies a sport steeped in centuries‑old ritual, demanding extraordinary skill, discipline, and a lifestyle that would make most modern athletes gasp. In this roundup of 10 fascinating facts about sumo, we’ll peel back the curtain to reveal everything from bizarre diets to mafia ties, and even the surprising presence of women in the ring.
10 Fascinating Facts: Sumo Secrets
10 No Japanese Yokozunas
The title yokozuna represents the pinnacle of sumo achievement, akin to a black belt in martial arts, but without a rigid checklist. Historically, the rank was an exclusive club for Japanese wrestlers, keeping foreigners (or gaijin) out of its highest echelons. One of the most famous non‑Japanese hopefuls, Konishiki, a Hawaiian‑born behemoth, once held the record for the heaviest sumo wrestler at 287 kg (633 lb) on a 184 cm (6′1½″) frame. Yet, his path to yokozuna was blocked.
That barrier finally crumbled in 1993 when another Hawaiian, Chad Rowan, entered the sumo world under the shikona “Akebono.” Standing 203 cm (6′8″) tall and weighing over 227 kg (500 lb), Akebono shattered the glass ceiling as the first foreign yokozuna. Since then, the landscape has shifted dramatically. Although Japanese wrestlers still compete, the rank has been dominated by non‑Japanese athletes—particularly Mongolians and Eastern Europeans—who leverage distinct fighting styles and sheer power. In fact, the three active yokozunas today all hail from Mongolia, and Japan has not produced a yokozuna in over a decade.
9 Canada’s Only Sumo Wrestler
Canada is famed for ice hockey, maple syrup, and polite strangers—not sumo. Yet, the nation produced a singular rikishi named John Tenta from British Columbia. Tenta’s athletic résumé was eclectic: he wrestled, played football, and even tried rugby while attending Louisiana State University. A chance encounter with a traveling sumo wrestler led him to Japan, where he adopted the shikona “Kototenta” (literally “Tenta the Harp”).
Although he found moderate success in the dohyo, the grueling demands of sumo proved unsustainable. Adding to his woes, the Japanese sumo establishment required him to undergo painful skin‑graft surgery to erase a large tiger tattoo—a nod to his college mascot—that conflicted with sumo’s aesthetic standards. After stepping away from the sport, Tenta reinvented himself as a professional wrestler in the WWF, performing under the moniker “Earthquake,” a villainous role that saw him clash with icons like Hulk Hogan and even tower over Andre the Giant. Tragically, the former sumo star succumbed to bladder cancer in 2006 at the age of 42.
8 Sumo Marathon
Marathon runners typically boast lean, wiry builds, but in 2011 a 180‑kg (396‑lb) sumo wrestler named Kelly Gneiting proved that endurance knows no size limits. Gneiting entered the Los Angeles Marathon and managed to jog the first 13 km (8 mi) before his legs forced him into a walking pace. The trek took a staggering 9 hours, 48 minutes, and 52 seconds—so long that city streets reopened before he crossed the finish line, compelling him to navigate sidewalks and wait at traffic signals.
Gneiting described a “delirious” state after the 16‑km (10‑mi) mark, yet he soldiered on despite inclement weather. The final five miles tested his resolve, prompting him to mutter, “If I have to crawl, I will.” His perseverance earned him a Guinness World Record as the heaviest individual to complete a marathon, surpassing the previous record holder who weighed 125 kg (275 lb).
7 Referees And Seppuku
Most sports fans love to hate referees, but in sumo the gyoji (referee) holds a position steeped in honor. Each gyoji carries a ceremonial knife, symbolizing a readiness to commit seppuku should a grave error occur—a dramatic gesture that underscores the weight of their calls. While actual suicide never transpires, a serious mistake traditionally prompts a gyoji to tender his resignation to the Japan Sumo Association.
Beyond the symbolism, the role can be perilous. Gyoji are intentionally diminutive, providing a stark visual contrast to the massive wrestlers they oversee. In January 2012, an unsettling incident captured on video showed referee Shozaburo Kimura being knocked unconscious after being thrust out of the ring during a bout, highlighting the physical dangers inherent in the position.
6 Diet
While most modern diets aim to shed pounds, sumo wrestlers deliberately bulk up. The sport lacks weight classes, meaning a heavier competitor enjoys a distinct advantage in overpowering lighter opponents. Consequently, rikishi follow a meticulously planned feeding regimen designed to maximize mass.
Training commences at dawn, often on an empty stomach to slow metabolism. Midday brings a protein‑rich stew called chankonabe, brimming with meat, vegetables, and rice, accompanied by a variety of side dishes. Wrestlers consume enough to induce nausea, then retreat to a prolonged nap, allowing calories to settle and convert into muscle and fat. A second, equally massive meal follows dinner, after which they finally retire for the night.
5 Fixing Matches
Sumo’s popularity has waned in recent years, with younger audiences gravitating toward baseball, soccer, and even golf. Unexpectedly, the yakuza—Japan’s organized crime syndicate—has infiltrated the sport, leveraging extortion tactics against wrestlers, especially those who gamble, an illegal activity in Japan. In 2010, prominent rikishi Kotomitsuki was expelled after admitting to betting on baseball games.
Beyond external pressure, internal corruption has plagued sumo. Rumors of match‑fixing surfaced for decades, famously examined in the 2005 book Freakonomics, which highlighted statistical anomalies suggesting collusion. For instance, a wrestler with a 7‑7 record might deliberately lose to a rival with an 8‑6 record, ensuring both finish with winning records. The defeated wrestler would then owe a favor, likely returning the favor in a future bout. In 2011, the Japan Sumo Association confirmed widespread match‑fixing, revealing secret payouts and choreographed bouts reminiscent of professional wrestling. That year, the association canceled the March grand tournament—the first cancellation since 1946.
4 Pavel Bojar, The Skinny Sumo
Not every sumo wrestler fits the stereotypical mountain‑range image; some rely on speed and technique. Czech athlete Pavel Bojar, competing under the shikona “Takanoyama,” weighed a modest 98 kg (216 lb) on a 185‑cm (6′1″) frame. Desperate to add bulk, Bojar was caught using insulin in 2011, earning a warning from officials.
His lighter frame forced him to adopt a throwing‑centric style, exploiting opponents’ momentum through techniques such as the overarm throw (uwatenage), underarm throw (shitatenage), and hook throw (kakenage). Despite the weight disadvantage, Bojar ascended to the top‑tier makuuchi division, though he struggled against elite competitors, experiencing multiple promotions and demotions before retiring in 2014.
3 Life In The Stables
One might assume that sumo wrestlers spend their days lounging, but the reality is far harsher. Their daily routine mirrors that of a strict regiment, comparable to a prison’s schedule. Training is described as “torturous,” involving relentless body‑weight drills, strength work, and endless bouts of shoving against unforgiving opponents. Financially, rikishi only begin earning a salary once they breach the upper ranks; until then, they serve as attendants for senior stable‑mates.
The sumo lifestyle is more a cultural tradition than a modern profession. Wrestlers must don traditional attire, are prohibited from driving, and endure health challenges linked to their size. Studies show that sumo wrestlers typically die a decade earlier than the average male, plagued by joint degeneration, kidney and liver ailments, hormonal imbalances, and other serious conditions.
2 Hazing
Hazing pervades many sports, ranging from harmless pranks to outright abuse. In 2014, a harrowing case emerged from a New Jersey high school where freshman football players were allegedly sexually abused by upperclassmen. Sumo, too, has its dark chapters. Traditional hazing in stables obliges junior wrestlers to act as servants—cooking, cleaning, and even, according to some tales, performing unsavory tasks like wiping the rear ends of heavyweight seniors.
The most chilling incident unfolded in June 2007 at the Tokitsukaze stable when 17‑year‑old Takashi Saito died during training. Initially reported as cardiac arrest, an autopsy revealed severe beating. Saito, who repeatedly attempted to leave the stable, was bound to a pole and assaulted with a beer bottle and baseball bat by three wrestlers under the orders of stable master Junichi Yamamoto, who claimed Saito’s “vague attitude” warranted punishment. The assault left his jaw dangling from his skull. Yamamoto tried to conceal the crime by suggesting cremation to destroy evidence, but the victim’s father demanded an investigation. Yamamoto received a six‑year prison sentence; the three wrestlers were given suspended sentences. Yamamoto later died of lung cancer in August 2014.
1 Women
Most professional sports are male‑dominated, and even those with women’s divisions often see a stark pay gap. In sumo, women face an even harsher barrier: they are prohibited from stepping onto the dohyo, the sacred ring, because menstruation is deemed “unclean” in traditional belief.
This exclusion came to a head in 2000 when Osaka’s governor, Fusae Ota—a woman—was supposed to present the Osaka Governor’s Prize to the tournament champion. Tradition forced her to stand ringside while a male representative handed over the award, underscoring the gender bias embedded in sumo culture.
While women’s sumo once existed as a popular attraction, it was largely entertainment orchestrated by brothels, known as onnazumo. Contemporary female sumo groups occasionally emerge, even in the United States, but they remain fringe performances rather than recognized competitive sport.
Mike Devlin is an aspiring novelist.