Sone was born in Nagato Province in Chōshū Domain (present-day Yamaguchi prefecture, his adopted father was a samurai from Hagi.

After the Meiji Restoration, Sone was sent to France for studies, and on his return to Japan served in the War Ministry.

Later, he served as director of the Cabinet Gazette Bureau, Secretary of the Cabinet Legislation Bureau and other posts, in 1890 he became the first Chief Secretary of the House of Representatives of the first session of the Diet of Japan.

He became a Privy Councillor in 1906, and elevated in status to viscount (shishaku) the following year.

[2] Sone was opposed to the Japanese annexation of Korea, but was forced to resign from his post in May 1910 due to illness and died a few months later.