Sonoda was a page to the lord of the clan when a boy. When Kiyotaka Kuroda was appointed deputy chief of the Hokkaido Development Board, Jittoku followed Kuroda to the island. After the board was abolished in 1881, he organized the Hokkaido Kyodo Marine Transportation Company on the basis of the influence of the Satsuma clique fostered in Hokkaido.
The firm merged with the Nippon Kyodo Transportation Company. Then it was amalgamated into the Mitsubishi Company in 1885, emerging as the Nihon Yusen Kaisha. Sonoda and Motoi Hori, manager of the N.Y.K.'s Hakodate branch, founded the Hokkaido Coal Mining and Railway Company and he became its president. His company purchased government railroads on Hokkaido totaling 62 miles and otherwise was given special privileges from the government.
Sonoda also established the Hakodate Docks. He became managing director of the Hakodate Hydroelectric Power Company in 1912 and held executive posts in many other companies and banks.