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. The Japanese and American governments together set up the Special Action Committee on Okinawa (SACO) to deal with the problems. In 1996, the U.S. and Japanese government agreed to closure or relocation of various military bases, including the Marine Corps Air Station Futenma, the most prominent based in the centre of Ginowan city's residential area. The move has however not happened as on June 2017 due to various issues. In 1995, he inaugurated the monument Cornerstone of Peace which commemorated more than 200,000 people who died in the Okinawa Battle, including U.S. soldiers.