Sakurai was born in Nagoya, although his official records list Hagi city, Yamaguchi prefecture as his hometown.

After Sakurai attended military preparatory schools in Nagoya and Tokyo, he graduated from the 23rd class of the Imperial Japanese Army Academy in 1911 and served as a junior officer with the IJA 53rd Infantry Regiment.

With the Second Sino-Japanese War ongoing, Sakurai was assigned command of the Infantry group of IJA 22nd Division in July 1937.

It participated at the Battle of Wuhan, although its primary duty was initially to serve as a garrison force for the Hangzhou area.

[2] After the end of the war, he spent two years in a prisoner camp in Burma with his soldiers, refusing repatriation until the last of his men could depart.