His parents ran a yakiniku restaurant.
In junior high school Okamoto did judo and participated in prefectural competitions in the third grade.
Amongst his opponents was the future top division sumo wrestler Chiyohakuho.
Although he had no experience in sumo, he was spotted by scouts from the Michinoku stable and recommended to its stablemaster, ex ōzeki Kirishima.
Okamoto was not aware of Kirishima's sumo career but was convinced by his passion for sumo to join Michinoku stable.
He made his professional debut in March 1999.
He scored six wins against just one loss in his first official tournament.
He came close to promotion to the sekitori level in May 2006 with a 4-3 record at makushita #3 but missed out and had to wait until November 2007 when a 5-2 at makushita #4 earned him promotion to the jūryō division.
He was the first member of Michinoku stable to do so since ex-Kirishima took over the stable in 1997.
In his jūryō debut in January 2008 he lost eight bouts in the first ten days but then recovered to win his last five matches in a row.
However, after losing scores in three tournaments from January to May 2010 he was demoted back to makushita.
 He never reached the top division, and the highest rank he achieved was jūryō 4.
His career record over 72 tournaments was 310 wins against 291 losses.
His parents ran a yakiniku restaurant. In junior high school Okamoto did judo and participated in prefectural competitions in the third grade. Amongst his opponents was the future top division sumo wrestler Chiyohakuho. Although he had no experience in sumo, he was spotted by scouts from the Michinoku stable and recommended to its stablemaster, ex ōzeki Kirishima. Okamoto was not aware of Kirishima's sumo career but was convinced by his passion for sumo to join Michinoku stable. He made his professional debut in March 1999. He scored six wins against just one loss in his first official tournament. He came close to promotion to the sekitori level in May 2006 with a 4-3 record at makushita #3 but missed out and had to wait until November 2007 when a 5-2 at makushita #4 earned him promotion to the jūryō division. He was the first member of Michinoku stable to do so since ex-Kirishima took over the stable in 1997. In his jūryō debut in January 2008 he lost eight bouts in the first ten days but then recovered to win his last five matches in a row. However, after losing scores in three tournaments from January to May 2010 he was demoted back to makushita.  He never reached the top division, and the highest rank he achieved was jūryō 4. His career record over 72 tournaments was 310 wins against 291 losses.
Kirinowaka Tarō