TOKYO (AFP) - Japan's ancient sport of sumo suffered another humiliating blow Wednesday (Nov 29) when grand champion Harumafuji retired after a brutal assault on a rival wrestler while out drinking, his gym boss said.
Harumafuji's stable master Isegahama told local media the Mongolian "yokozuna" had caused embarrassment to the Japan Sumo Association (JSA) over an incident last month that left countryman Takanoiwa with a fractured skull.
His exit mirrors that of another top-ranked Mongolian, Asashoryu, who promptly stepped down in 2010 after being accused of breaking a man's nose in a drunken brawl outside a Tokyo nightclub.
Yokozuna are expected to be beyond moral reproach but the writing was on the wall for Harumafuji after he confessed to hitting Takanoiwa for texting his girlfriend while he was scolding him over his poor attitude.
The 33-year-old Harumafuji, who reached sumo's hallowed rank five years ago and whose real name is Davaanyam Byambadorj, denied reports he had used a beer bottle in the attack but admitted punching Takanoiwa and bashing him with a karaoke remote control.
Takanoiwa, 27, was hospitalised after suffering concussion and a fractured skull base, according to local media.
His stable master subsequently reported the incident to the police, who invited Harumafuji in for questioning.
The latest scandal has reopened old wounds in the closeted world of sumo after an increase in violence, allegations of illegal betting, links with crime syndicates and drug busts shook the sport in recent years.
A sumo stable-master was sentenced to six years in prison in 2007 after a trainee wrestler was beaten to death, triggering outrage across Japan.
Another gym boss narrowly escaped criminal punishment after whacking three wrestlers with a golf club for breaking curfew.
The 135kg Harumafuji, whose nifty technique makes up for his relative lack of size, won nine Emperor's Cups before his fall from grace.
Historians claim sumo dates back more than 2,000 years and the sport retains many Shinto religious overtones.
Breaches of its strict protocol are frowned upon, although the JSA has been accused of picking on Mongolian wrestlers, who critics claim lack "dignity".
However, the trail-blazing Asashoryu stretched their patience to breaking point with his repeated rule-breaking, despite roaring to 25 major championships.
He was ordered to clean up his act after a sparking a soapy punch-up with a rival wrestler during a soak in a communal bath.
Asashoryu was subsequently banned for forging a doctor's note for an apparent back injury before being caught playing in a charity football match wearing a Wayne Rooney shirt.
Another Mongolian grand champion Hakuho, seen as a gentle giant, has battled almost single-handedly to repair sumo's tarnished image.
But even he was accused of breaching etiquette in 2015 when he let rip at a decision to repeat a bout deemed too close to call, prompting more tut-tutting from officials.