was a politician and cabinet minister in the pre-war Empire of Japan.
à Âishi was a native of Tosa Province (modern-day Kà Âchi Prefecture), where his father was a samurai in the service of Tosa Domain. In 1873, he joined with Itagaki Taisuke and became an important member of the Freedom and People's Rights Movement. He became one of the leaders of the Jiyà «tà  political party in 1881. However, he had a falling out with Itagaki in 1882 and left the party. He subsequently joined with Gotà  Shà Âjirà ÂâÂÂs daidà  danketsu (coalition) movement in 1887. In 1892, he was appointed to the Japanese legation in Seoul, Korea. He was back in Japan by 1896, and was one of the founding members of the Shimpotà  political party. Under the short-lived 1st à Âkuma Shigenobu administration in 1898, Oishi was appointed Minister of Agriculture and Commerce.
à Âishi later joined the Rikken Kokumintà  and was at one point a contender against Inukai Tsuyoshi for its leadership. In 1913, he broke with Inukai, and joined Katsura Tarà ÂâÂÂs new Rikken Dà Âshikai, where he was ranked as one of its five leaders. He retired from politics in 1915, after having been elected to the Lower House of the Diet of Japan for six terms.