Haraguchi was born on 2 April 1847[1] to a samurai-class family in the Mori region of Bungo Province (in present-day Ōita Prefecture),[3] located on the island of Kyushu.

[4] Later in his career, from August 1890 to April 1892,[1][5] he was dispatched to the German Empire to further his military education,[3] where he served from 1890 to 1891 under Prussian general Jakob Meckel in the 2nd Infantry Regiment stationed in Mainz.

[3] Following the Japanese occupation of Korea at the start of the Russo-Japanese War, Haraguchi commanded the newly established Korean Garrison Army from 11 March[6] to 8 September 1904, when he was replaced by field marshal Hasegawa Yoshimichi.

[7] In July 1904, he declared martial law on key railroads and near telegraph lines in response to local unrest, writing the month prior to Minister of War Terauchi Masatake:[8] We try generally to be conciliatory in our policies toward the Korean people, but we have to be very severe in punishing anyone who willfully, with malign intent, sabotages the activities of the Japanese army.

[2] In January 1905, he attained the rank of lieutenant general, and soon thereafter assumed command of the newly raised, 14,000-strong[9] IJA 13th Division, which he led during the invasion of Sakhalin.