Primarily known as an illustrator and manga artist, Okano graduated from the Western-style painting department of the Tokyo School of Fine Arts in 1902.  He also studied under Kuroda Seiki at the Hakubakai (White Horse Society) and went on to be a founder of its successor association, the Kōfūkai, in 1912.  He taught for many years at as Gakushuin Women’s College.

From 1925 to 1927 he was in Europe on a research mission for the Imperial Household Agency, spending time in France and Italy.  

He contributed to a number of sketch tour books including the five volume Sketches and Travel Notes on Japanese Sights (Nihon meishō shasei kikō 日本名勝写生紀行),published 1909-1912.  This work was a collaboration along with four other Hakubakai artists,  Nakazawa Hiromitsu (1880-1942 ), Yamamoto Morinosuke (1877-1928), Kobayashi Shōkichi  (1887-1946) and Atomi Tai (1884-1953).  Okano did the cover designs for each volume in an art nouveau style. For the cover of Volume 1, shown below, Okano presents the seals of the five artists along with a caricature of each artist.  Okano’s “ei” 栄 seal appears second from the left. 

The woodcuts for the entire series were cut by Igami Bonkotsu and printed mainly by Nishimura Kumakichi, with the assistance of Nakamura Sanjirō and Oyama Kangorō.¹