[2] More specifically, he served at the embassy in France (1918–1923), United States (1927–1930) and Manchukuo (1933–1936).

[6] Then Tani served as information chief and also, foreign minister in the cabinet of Hideki Tōjō.

[8][9] During his tenure, Japan continued to encourage a separate peace between Germany and the Soviet Union.

Since bureaucrats in the ministry of foreign affairs resented Tani,[2] on 21 April 1943, he was replaced by Mamoru Shigemitsu.

[10] After that, he received Shigemitsu's former post of Japanese ambassador in Nanjing to the Reorganized National Government of China.