Sumo grand champion Harumafuji announced he would retire to take responsibility for injuring a junior wrestler in an incident that has threatened to taint the image of Japan's national sport just as it was regaining popularity.
The 33-year-old Mongolian-born "yokozuna" (grand champion) had already apologised earlier this month after media reported he had beaten junior wrestler Takanoiwa while drinking at a restaurant-bar with other wrestlers.
"As 'yokozuka' I feel responsible for injuring Takanoiwa and so will retire from today," a stern-faced Harumafuji told a news conference carried live by several Japanese broadcasters in Fukuoka, southern Japan, site of the most recent tournament.
"I apologise from my heart to the people, sumo fans, the Japan Sumo Association, to supporters of my 'stable' (gym) and my 'oyakata' (coach) and his wife for causing such trouble."
Harumafuji gave no details of the incident - still under investigation by police - which media reports said occurred when he got angry because the younger wrestler was checking his smartphone after being chastised for a bad attitude.
Takanoiwa, 27, did not take part in the latest tournament due to his injuries, which the sumo association said included a fractured skull and concussion.
"I think it is my duty as a senior wrestler to correct and teach junior wrestlers when they are lacking in manners and civility," Harumafuji said. "But I went too far," he said, adding that the incident did not occur because he had been drinking.
The incident has highlighted sumo's struggle to reform harsh conditions that can breed violence in its closed, hierarchical world, although some wrestlers say there have been improvements in the decade since a trainee was beaten to death.
"Sumo, recognising its responsibility as the sport with the longest history in Japan, must stamp out violence so that the expectations of the people, including youth, are not again betrayed," Education Minister Yoshimasa Hayashi, whose ministry oversees sports, said in a parliamentary committee meeting.
