[1] After starting his career as a professor at the University of the Ryūkyūs, he wrote books in English and Japanese, mostly about the Battle of Okinawa and Japan–United States bilateral relations following World War II.

After his retirement as professor he was elected as governor and was best known for his strong stand against occupation of prefectural lands by military bases of United States, going against the Japanese central government at the time.

Ōta was born on 12 June 1925 on Kumejima Island, Okinawa and his family migrated during World War II.

He had a distinguished record as a governor, outspokenly arguing for the interests of the Okinawan people against both the United States military establishment in the Ryukyu Islands and the Japanese central government.

[5] In February 1995, reports from Washington prepared by Harvard professor Joseph Nye indicated their plans of deploying over 100,000 soldiers in Japan and South Korea.

[5] From 1996 to 1998, he actively worked to establish cordial relations with U.S. On 8 September 1996, he organized a plebiscite in his prefecture which brought results that about 60 percent of citizens who supported reduction of military bases.

[5] Due to Ōta's efforts, mass campaigns such as the Okinawa Women Act against Military Violence, which arranged a rally at Ginowan's Seaside Front on 21 October 1995, had nearly 85,000 people participating.

Obuchi supported the Liberal Democratic Party (LDP) candidate Keiichi Inamine for the governor's post in opposition to Ōta.

[4][7] Upon his death, Japanese Chief Cabinet Secretary Yoshihide Suga called him "an individual who energetically tackled Okinawa's base issues and (economic) development at a turbulent time.