| Native Name: | 平石 七太夫 (2代) |
| Hiraiwa Shichidayū II | |
| Birth Date: | 1801 |
| Birth Place: | Edo, Musashi Province, Japan |
| Weight: | 129kg (284lb) |
| Heya: | Tokiwayama → Kumegawa → Ikazuchi |
| Record: | 83-35-57-13 draws/4 holds |
| Debut: | February 1818 |
| Highestrank: | Ōzeki (March, 1839) |
| Retireddate: | February, 1840 |
| Eldername: | Kumegawa |
| Update: | October 2023 |
was a Japanese sumo wrestler from Edo, Musashi Province (now Tokyo). His highest rank was ōzeki. He is the first wrestler from Tokyo to have been promoted to this rank and the last until the promotion of Isenohama in 1914, 75 years later.[1]
Little is known about Hiraiwa. He began his wrestling career by joining Tokiwayama stable in the Edo-based sumo association. He eventually joined Kumegawa stable and made his debut in February 1818.
Upon promotion to the jūryō division in February 1829, he was given the shikona, or ring name,, but later changed it for . He reached the makuuchi division in February 1831. In 1835 he changed his shikona again to to evoke an early 19th-century ōzeki from Tottori prefecture. He was recruited as a wrestler for the Marugame Domain and made his san'yaku debut in 1836, reaching the rank of komusubi in February and sekiwake in November.[2] After spending three years in the junior ranks of san'yaku, he was finally promoted to ōzeki in March 1839 because Kotōzan was demoted from that same rank for that tournament, leaving the ranking unbalanced.[2] He maintained his rank for only one tournament and was demoted to the rank of sekiwake before regaining promotion for a single tournament before retiring.
After his retirement as a wrestler, he became an elder under the name Kumegawa, becoming a leading figure in the Sumo Association.[2] His tomb is located on the site of the Nanzo-in temple in Toshima, Tokyo. With him is buried the sixth generations of Kumegawa (makushita-wrestler Kiryūzan Reihachi I), as was traditional at the time.[3]
His ring name was later inherited by sekiwake in 1867.