Although the family held Buddhist beliefs, his younger brother Giichi converted to Christianity and became a Protestant missionary: he worked at churches in Manchuria, Vancouver Island, and Chicago and became the headmaster of YMCA in Tokyo.

"[2] Suga graduated from Meido Middle School in Hiroshima and then the Imperial Japanese Army Academy in Tokyo, as a Second Lieutenant.

After the Japanese attack on Pearl Harbor, Suga volunteered for service as a prison camp commander on an advice of his younger brother,[4] believing that his language skills would prove useful.

[5] On Borneo there were Japanese-run internment camps at Batu Lintang, Kuching, Sarawak, Jesselton (later Kota Kinabalu), Sandakan and briefly on Labuan island.

[11] In fact, his wife and three of his children survived the bombing though his sister Teru and brother-in-law Tamekichi Tanaka as well as his son Makoto were killed.

[12][13] Suga attended the official surrender of the Japanese forces in the Kuching area by their commander, Major-General Hiyoe Yamamura, on board HMAS Kapunda on 11 September 1945.

[14] Later that day Suga officially surrendered to Brigadier Thomas Eastick, commander of Kuching Force — a detachment from the Australian 9th Division — at Batu Lintang camp.

Although Keith admired some of his personal qualities and felt that he had saved the life of her husband, who was also interned in the camp, she also recorded: "Against this, I place the fact that all prisoners in Borneo were inexorably moving towards starvation.

A large number of the graves of prisoners from Batu Lintang now at Labuan are unidentified: after the Japanese surrender Suga destroyed many camp records.