Okumura Eisaku was a career military officer in the Imperial Army. As a young man, he was sent to Austria-Hungary twice (before and after the Russo-Japanese War), during which time he kept a diary. Okumura Mutsuyo, his granddaughter, inherited the diary and has transcribed and annotated it. It is a unique primary source for Late Meiji period history, and appears to be the only diary written by a military officer stationed overseas during that period.
In 2021, Okumura Mutsuyo donated the original diary to Center for Military History of the National Institute for Defense Studies (防衛省防衛研究所・戦史研究センター), where it is kept in the Military Archives (史料室).
Unannotated transcription of the diary