 From August 1929, Okamura was appointed as Assistant Director of Human Resources Bureau in the Ministry of the Army.He was involved in the March incident, a failed coup d'etat attempt to establish a military dictatorship headed by General Kazushige Ugaki , but received no punishment.On May 31, the same year, he reached the conclusion of the Heiwa and Tanggu Agreement, which was the plenipotentiary of the National Government Army.