Kunisuke Okazaki was born in Wakayama Prefecture. His father was a karo with revenues of 400 koku as a direct retainer of the Kiishū Tokugawa family, and he was the first cousin of Mutsu Munemitsu. He was a cousin of Munemitsu Mutsu a foreign minister in the Meiji Era.
Kunisuke Okazaki accompanied Munemitsu Mutsu to the United States (1888), where he studied at Michigan University. Returnig to Japan (1890), he was elected to the House of Representatives (1891) and assisted Mutsu. After Mutsu died, he was the right-hand man of Toru Hoshi. He fought the feudalistic forces remaining in the political world and worked for constitutional politics. He started the "Constitution Protection" movement (1924), opposing the Cabinet of Viscount Keigo Kiyoura. Contributed much to the enactment of the Universal Suffrage Law. He was appointed Minister of Agriculture and Forestry in the Kato Cabinet (1925).
Kunisuke Okazaki was a leader of the Seiyukai Party, he was elected to the House of Representatives 10 times. He was made a member of the House of Peers (1928).
