The resignation of the national women's judo coach, who beat athletes with a bamboo sword, was a nasty reminder of how Japan's sporting world still draws on the traditions that led the country to war last century, experts say.
This file picture taken on July 31, 2012 shows Japanese women's judo head coach Ryuji Sonoda at the London Olympics. Sonoda quit in disgrace on February 1 after 15 of his charges accused him and his staff of slapping, kicking and beating them during training in the run up to the Olympics.
And, they say, despite the bravery of the judokas who risked their careers to bring it to light, the culture of coercion and corporal punishment is so ingrained that it will die hard.
Ryuji Sonoda quit in disgrace on February 1 after 15 of his charges accused him and his staff of slapping, kicking and beating them during training in the run up to the London Olympics.
Sonoda, 39, who doubles as a judo instructor for Tokyo police, was also heard telling members of the squad to "drop dead" during humiliating dressing downs.
His boss Kazuo Yoshimura, the technical director at the All-Japan Judo Federation, also stepped down later along with one of Sonoda's assistant coaches.
But the women, none of whom has been named publicly, say despite the seriousness of the charges, multiple complaints were only acted on by the male-dominated federation and the Japanese Olympic Committee when the scandal was exposed by the media in late January.
"We were deeply hurt both physically and mentally. Some of us were reduced to tears and others were exhausted," they said in a statement, adding they took a stand "for the future of women's judo".
The explosive case came weeks after a teenager killed himself following repeated physical abuse from his high school basketball coach, reigniting a national debate on widespread corporal punishment in schools and sport.
Worried about negative fallout from these incidents on Tokyo's bid for the 2020 Summer Olympics, the government announced an independent body to investigate and prevent the abuse of athletes by their coaches in all sports.
But, says Hidenori Tomozoe, a professor of sports ethics at Tokyo's Waseda University, the problem is a systemic one.
Sonoda, the judo coach, said he had been beaten himself by coaches but "I never took it as physical punishment." He added he had struck his judokas "as I wished them to stay strong and overcome mental barriers".
Physical punishment is frequently tolerated in schools -- nurturing grounds for sports in Japan -- as an effective tool to produce athletes, says Tomozoe.
He said the tradition dates to 1925 when the government started sending military officers into schools as drill instructors to provide jobs for them after World War I.
This coincided with Japan's march towards militarism and the acquisitive and brutal warring of the following two decades.
"They beat students and otherwise acted violently against them in the name of training," he told AFP. "After the war, they were purged but the atmosphere or ethos they created has remained in school culture.
"It is like an accumulation of pus over 100 years and will be never be cured in a year or two," he said.
A law was enacted in 1947 to prohibit the physical discipline of students by teachers. However, such practices have continued in the absence of statutory penalties for offenders.
Japan's professional sporting world is no stranger to tales of extreme physical abuse.
In 2007, a 17-year-old sumo apprentice died after a hazing incident involving his stable master and senior wrestlers. The stable master, who struck the teen with a beer bottle, was sentenced to five years' jail for negligence resulting in death.
Former baseball star pitcher Masumi Kuwata, 44, recalled being beaten by his seniors when he played in school teams.
"Violent coaching in sports including baseball is carrying on the legacy of wartime military education," he said, adding that Japanese baseball adapted to spartan training and absolute obedience during the war.
"I never felt that the pain and fear of physical punishment had ever toughened me a bit," Kuwata told a seminar on violence in coaching.
He said was impressed when he observed training in school baseball in the United States during his 2007 stint with the Pittsburgh Pirates.
"There was no angry shouting or beating at all. They played baseball freely and leisurely. Such a background produces major leaguers."
Noriko Mizoguchi, who won a silver medal at the Barcelona Olympics and coached the French women's judo team from 2002-2004, said the petition by the 15 women was a "turning point in Japanese thinking".
"These women are worried they will be treated like criminals if Tokyo loses its Olympic bid," Mizoguchi, who teaches sports science at a university, told AFP.
"But I think rather they will become key players in making the bid a success because they embody the Olympic spirit that never condones discrimination and violence."