Oohata 【大旗】3 The Japanese surnames etymology dictionary.
Yamanashi-ken , Nagano-ken , Toukyou-to . Nagano-ken Saku-shi Beginning of Shimodakadate, Midoriokodare, Shimodakadagiri. A place name with a record since the Kamakura period. Nagano-ken Nagano-shi The vicinity of Yasugari Minato (formerly Odagiri) is a stopover. A place name with a record since the Warring States Period. There was a lodging of Mr. Odagiri on the same floor. Nagano-ken Kamiina-gun The vicinity of the Odagiri River flowing through Miyada-mura is a stopover. Nagano-ken Kamiina-gun Miyada-mura It was in the Odagiri Castle of Minami during Warring States Period. In the estimation Otagiri is old pronunciation. Tagiri means "torrent", "slopes eroded by the river".