Ooba 【大葉】4 The Japanese surnames etymology dictionary.
① variant of the 小川 . Okayama-ken Okayama-shi Kita Ward Marunouchi was in the Edo period in the Clan Okayama of the Clan office. Okayama-ken Kume-gun Misaki-chou Ohara was in the Edo period. In the same place descendents say "Ogawa" also called. 小川 reference.
② Toukyou-to Katsushika-ku Originated from the vicinity of Mizumoto (formerly Koji). A place name with a record since the Muromachi period. The place name was also written as "Ayu. Tradition in Shimane-ken western part (formerly Iwami-kuni). In the same place, Kooyu tells it to be old pronunciation.