[2] Oka was born in Kōchi Prefecture, the former feudal domain of Tosa.
He was employed at the Yorozu choho (Complete Morning Report), where he became friends with anarchist Kotoku Shusui, Sakai Toshihiko, and Kinoshita Naoe.
In 1902, Oka Shigeki immigrated to America,[3] where he became head of the San Francisco branch of the Heimin-sha (Society of Commoners).
He helped Kotoku Shusui make contact with American socialists, and anarchists during his stay in America.
[2] In 1943, he was recruited by the British Armed Forces to print propaganda materials, such as the Gunjin Shimbun [Soldier News], in Kolkata, India.