He graduated from Law Department, Tokyo University in 1895.
Chuji Shimo-oka was appointed counselor and secretary of Kumamoto, Kyoto and Ibaraki prefectures. He was appointed governor of Akita Prefecture (1906), vice-minister of Agriculture and Commerce (1912) and later chief secretary of Privy Council. Chuji Shimo-oka was appointed Home Vice-Minister (1914).
After leaving the government service, he was elected to the House of Representatives several times. Figured as leading member of the Kenseikai Party; was appointed Chief Civil Administrator of Government-General of Korea (1924).