Early military career Tani was born to a farming family in
Okayama Prefecture. He graduated from the 15th class of the
Imperial Japanese Army Academy in 1903, placing 16th in his class. One of his classmates, Yasusuke Nogi, was the younger son of General
Nogi Maresuke, and later died in combat during the
Russo-Japanese War. Tani also saw combat during that war as a second lieutenant in the
Guard's First Infantry Battalion, although his training at the academy had been in artillery. After the war, he graduated in third place from the 24th class of the
Army War College in 1912. Tani later wrote an account of his experiences in the war, together with first-hand accounts of survivors, which was published under the title . The book became a required textbook for the Army Staff College, although it was criticized by
Field Marshal Uehara Yusaku for inaccuracies. Tani was posted to
Great Britain as a
military attaché from 1915, and from August 1917 he was embedded in the front lines as an official
military observer for the Japanese government on the combat situation on the
Western Front in
World War I. After his return to Japan, in April 1919 he served as an instructor at the Army Staff College, and was reappointed to that position in February 1924. In February 1927 he was promoted to colonel and made commander of the IJA 61st Infantry Regiment. In August 1928, he became chief-of-staff of the
Nagoya-based
IJA 3rd Division. In May 1930, Tani was named to the
League of Nations Standing Committee on Military Aviation. He was promoted to major general in August 1930. He returned to Japan in 1932 to become Chairman of Military Investigation, and from August 1933 was commander of the
Guards 2nd Brigade. he was promoted to lieutenant general in August 1934. He served as commander of
Tokyo Bay Fortress from August 1934 to December 1935. He was then sent to
Kumamoto to oversee the reconstruction of the
IJA 6th Division.
World War II In July 1937, the IJA 6th Division was assigned to the
Japanese China Garrison Army, and immediately began combat operations in the
Second Sino-Japanese War starting with the ongoing
Battle of Beiping–Tianjin. Afterward, it participated in
Beiping–Hankou Railway Operation. In October 1937, the division was re-subordinated to
IJA 10th Army and attacked the Chinese troops concentration at
Hangzhou Bay. By December 1937, it shifted west to join the
IJA 18th division and
IJA 114th division in the
Battle of Nanking and ultimately in the
Nanjing Massacre. Returned to Japan at the end of 1937, Tani became commander of the
Central District Army until September 1939 when he went into the reserves. However, after the
Atomic bombing of Hiroshima, Tani was recalled to active service to take command of the
IJA 59th Army and concurrently the
Chugoku Regional Army District. These organizations were part of the last desperate defense effort by the
Empire of Japan to deter possible landings of
Allied forces in the
San'yo region of western
Honshū and consisted mostly of poorly trained
reservists,
conscripted students and
home guard militia. The IJA 59th Army was officially
demobilized after the
surrender of Japan on August 15, 1945.
Trial and execution . In February 1946, Tani was arrested on orders of the
American occupation authorities and charged with Class B and Class C
war crimes. At the request of the
Chinese government, he was extradited to China to stand trial at the
Nanjing War Crimes Tribunal in August 1946. Tani denied all charges at the trial, stating that his troops kept discipline, and the area of Nanjing assigned to his division had been largely evacuated due to the ferocity of the battle. Furthermore, none of the witnesses against him could identify his unit numbers, and indeed the evidence presented to the court pertained to troops and areas of the city under General
Kesago Nakajima and General
Shigeharu Suematsu. However, the presiding judge refused Tani's request to call on his chief of staff and surviving junior officers as witnesses, and stated that since the various atrocities which occurred in Nanjing were testified to by hundreds of surviving witness as well as several foreigners from
Nanking Safety Zone, he was unwilling and unable to divide responsibility. According to the ruling of the court, all of the Japanese commanders involved in the
Battle of Nanjing had an equally shared responsibility for atrocities which occurred during the
Rape of Nanjing, and this included Generals
Iwane Matsui,
Heisuke Yanagawa and
Sadao Ushijima as well as Nakajima, Suematsu and Tani. He was consequently
sentenced to death as a BC-class war criminal. On 26 April 1947 he was escorted to his execution spot at Mount Yuhuatai and publicly executed by shooting. The crowds of Chinese civilians who witnessed the execution were cursing at him for the atrocities he committed. ==Family==