At school he did judo, but after a sumo tournament in the area, he was recruited to Hanakago stable by Kaiketsu Masateru and fought his first bout in March 1978, aged 15.

In November 1983, ranked as maegashira 3, he won his first special prize and three gold stars by defeating all three yokozuna (Kitanoumi, Chiyonofuji and Takanosato).

In the tournament that month, he defeated three yokozuna and three ōzeki and won special prizes for Fighting Spirit and Outstanding Performance.

He missed most of the July tournament due to a knee injury, then in September he became the first yokozuna ever to have make-koshi, or turn in a losing score of just 7 wins out of 15 bouts.

[3] Ōnokuni missed the following tournament in May due to a fever resulting from a skin infection,[3] and upon his return in July he was defeated four times in the first eight days.

He announced his retirement from sumo at the age of just 28 after being beaten by Akinoshima on day 8, leaving a disappointing record of just one yūshō and two runner-up performances in his 23 tournaments at yokozuna rank.

[3] Ōnokuni has remained in the sumo world as an oyakata, or elder, and opened his own training stable, Shibatayama-beya in 1999.

In March 2008 the stable produced its first sekitori, Daiyūbu, but he spent only one tournament in jūryō and retired suddenly in June 2010 after falling out with his stablemaster.

In March 2016 Shibatayama and one of his wrestlers, Komanokuni, were ordered by the Tokyo District Court to pay 32.4 million yen (287,500 USD) in compensation to another former wrestler who the court ruled had faced "daily abuse" since joining in 2008 and had to undergo four surgeries for a detached retina, eventually losing sight in the eye in 2013.

He was elected to the board of directors of the Sumo Association in 2018 and has the role of head of the public relations department.

Sanshō key: F=Fighting spirit; O=Outstanding performance; T=Technique     Also shown: ★=Kinboshi; P=Playoff(s) Divisions: Makuuchi — Jūryō — Makushita — Sandanme — Jonidan — Jonokuchi