He attended military preparatory schools, and graduated from the 26th class of the Imperial Japanese Army Academy in May 1914 and was initially assigned to the IJA 54th Infantry Regiment.

As a major in 1931, he was assigned to the military intelligence section of the Kwantung Army and served as head of the Mukden Special Operations Office.

His division was also ordered to invade the Akyab region of Burma from 11 January 1944; however, his offensive was destroyed by British reinforcements and air supremacy and retreated to avoid encirclement.

112th regiment was by that time down to roughly 400 men from original 3000, and was faced by British forces including "a hundred" of artillery pieces, according to survivor's testimony.

Hanaya had a reputation for brutalizing the officers under his command, and was universally hated, maintaining his position despite numerous complaints only due to direct support from Hideki Tojo.