This guide is mainly based on a part of National Diet Library’s research guide (in Japanese) which provides variety of statistical aspects on different wars in modern Japan. Many resources listed in the guides are held by Yale University which are mentioned below. Although some statistics include names of statistics and its category titles in English, many require Japanese language capacity to fully benefit from the data.
General
Historical Statistics of Japan = Nihon chōki tōkei sōran (v. 5) 日本長期統計総覧
http://hdl.handle.net/10079/bibid/8691690
Includes statistics such as expenses and casualties of individual wars.
Sino-Japanese War 1894-95
Nisshin Sensō tōkeishū 日清戦争統計集
http://hdl.handle.net/10079/bibid/7871540
Nihon Kaigunshi (v.7) 日本海軍史
http://hdl.handle.net/10079/bibid/1115387
Ad hoc military expense of Sino-Japanese War (p.137-137)
Russo-Japanese War 1904-05
Nihon Kaigunshi (v.7) 日本海軍史
http://hdl.handle.net/10079/bibid/1115387
Ad hoc military expense of Russo-Japanese War (p.137-137)
テーマで見る日露戦争by Japan Center for Asian Historical Records (JACAR)
http://www.jacar.go.jp/nichiro/keyword06.htm
Expenses and casualties of the war, consumption of bullets and cannonballs, etc
Nichi-Ro senso tokeishu 日露戦争統計集
(Yale University does not own the titles. Check Borrow Direct.)
Information and statistics on recruitment and demobilization; mission and strategies; fortification; commissariat; transportation and communication; sanitation; expense; education; manpower, war-horse, weapon; uniform; foraging; combat supplies; buildings; quarantines; rewards; punishment ; administrations of occupied territories ; war prisoners ; rescue teams.
Kanketsu Shōwa kokusei sōran 完結昭和国勢総覽
http://hdl.handle.net/10079/bibid/9672599
Various statistics on the Army and Navy structures such as call-ups and drafted numbers of soldiers in Army, number of Korean and Taiwanese soldiers in Navy as well as numbers of air carriers and navy ships and its damages by the war.
Pacific War 1941-1945
Shiryō Taiheiyō Sensō higai chōsa hōkoku=Report on damage and casualties in Japan caused by World War II
史料・太平洋戦争被害調查報告
http://hdl.handle.net/10079/bibid/1105174
Statistics for various damages of the war such casualty by aerial attacks and atomic bombs, damage to national wealth, damage to industrial production, facilities and equipment, etc.
Kanketsu Shōwa kokusei sōran 完結昭和国勢総覽
http://hdl.handle.net/10079/bibid/9672599
Various statistics on the Army and Navy structures such as call-ups and drafted numbers of soldiers in Army, number of Korean and Taiwanese soldiers in the Navy as well as numbers of aircraft carriers and ships.