However, he ended up dropping out of high school and was introduced by an acquaintance to Hakkaku-oyakata, the 61st yokozuna Hokutoumi, who persuaded him to join his Hakkaku stable.

He changed his shikona to Okinoumi, a reference to his birthplace of Okinoshima (a tiny and remote island in Western Japan) which had been suggested by his father.

Fighting as Okinoumi once again, in January 2010 he won promotion to the top makuuchi division, becoming the first wrestler from Shimane Prefecture to do so in 88 years.

Ranked at jūryō 8, a 10–5 record was enough to return him to the top division for the November tournament, where he secured his majority of wins on the final day.

His best performance to date came in the January 2011 tournament where he finished runner-up to yokozuna Hakuhō and received his first sanshō award, for Fighting Spirit.

Securing his majority of wins on the final day of the July tournament, he reached a new highest rank of maegashira 1 in September.

He achieved his first gold star win against Harumafuji in November 2012, and his second Fighting Spirit award and second runner-up performance at maegashira 7 in March 2013.

In the November 2017 tournament Okinoumi was a runner-up to Hakuhō with an 11–4 record, and was awarded his third Fighting Spirit prize, shared with Aminishiki.

[13] At his retirement press conference, Okinoumi said that for several years he had to rely on mental strength to overcome his inability to perform his style of sumo and that it had recently become too exhausting.

About 300 people took turns in the ceremonial snipping of Okinoumi's ōichōmage before the final cut was made by his stablemaster and Sumo Association chairman Hakkaku.

The matches were held in a traditional sumo style unique to Okinoshima called okikoten-zumō, which involved ringside spectators throwing generous amounts of salt toward the competitors as a method of encouragement.

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