西園寺公望
In 1911, Ishimoto was appointed Army Minister under the cabinet of Prime Minister Saionji Kinmochi. At the time, there was a major controversy between the Army's demand for an expansion by two additional infantry divisions, and the cabinet's insistence that there was not enough money in the budget to pay for the expansion. He died while in office, at the relatively young age of 59, with the issue unresolved. His grave is located at the temple of Tenno-ji, located in Taitō, Tokyo.