Shibatayama stablemaster is one of the more visible members of the Japan Sumo Association's board of directors.
As head of the public relations department, he is the one who announces many major decisions to the press and, along with Chairman Hakkaku, is the person most often quoted in news stories.
As an active rikishi he reached the sport's highest rank of yokozuna. His time at the rank was relatively short, however — a little under four years — and he won just one title while at the rank.
That March 1988 Emperor's Cup gave Onokuni a total of two for his career, with the first being a 15-0 mark in May 1987 while ranked at ozeki.
His debut championship was also the first time any rikishi other than Chiyonofuji had lifted the Emperor's Cup in the current Kokugikan — something that had taken 2½ years as the legendary yokozuna had won the first seven tournaments held in the building after its opening.
Interestingly, Onokuni's promotion to the top rank in sumo didn't follow his perfect championship or indeed the one after — in which he managed a runner-up performance.
It would take two straight second-place finishes following his 15-0 triumph before he received the white rope.
Although just 94 kg when he joined sumo, Onokuni was more than twice that at his heaviest, and is to date the only Japanese-born yokozuna to weigh over 200 kg, with only Hawaiians Akebono and Musashimaru heavier at the rank.
Onokuni's love of sweets and cakes is well known and he has often appeared on food-related television shows.
His stable, Shibatayama, is currently the only one located in the western part of Tokyo and is unusual in having the practice ring located in the basement.