Prosecutors in Japan have charged former sumo wrestling grand champion Harumafuji with assault after he fractured the skull of a lower-ranking rival in a bar brawl.

The 33-year-old Mongolian-born wrestler was served the order by prosecutors in Tottori, western Japan, in a move to seek the payment of fines rather than a trial.

The former yokozuna – or senior wrestler – retired last month after injuring fellow Mongolian wrestler Takanoiwa while drinking at a restaurant-bar with other wrestlers in Tottori, an incident that has threatened to taint the image of Japan’s national sport just as it was regaining popularity.

The scandal gripped Japan as details of the incident emerged, and led local news bulletins despite the North Korean missile launch.

Harumafuji has admitted to punching Takanoiwa and hitting him with a karaoke remote control, causing a skull fracture.

A report by the Japan Sumo Association’s crisis management committee found that Harumafuji, angered that his younger rival was checking his smart phone after being chastised for a bad attitude by yokozuna Hakuho.

The summary indictment was filed against Harumafuji for causing a chop wound with the remote control, an official at the local prosecutors office said.

Following the summary indictment, Harumafuji’s lawyer released a statement on his behalf:

“Because of this incident, my life as Harumafuji is now set to be sharply different from what I thought it would be,” he said in the statement.

Sumo grand champion Harumafuji pushes opponent Takanoiwa out of the ring.

“I have a feeling of chagrin, to be honest. But the responsibility is all mine.”

The incident has highlighted sumos’ 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 wrestling is an ancient Japanese sport, whose exponents are expected to exhibit high moral standards.

-ABC