According to the written confession of Giichi Sumioka in May 1955, he was born in Osaka, Japan in 1917. In 1939, he joined the army and invaded Xuancheng County, Anhui Province, China in the same month. After Japan's surrender in August 1945, he took refuge in Yan Xishan's troops. He was arrested on 10 July 1948 in Taiyuan, Shanxi.
January 1940:while training the new recruits in Xuancheng, Anhui, "stabbed to death about 10 captives from the New Fourth Army and the anti-Japanese army as 'educational materials'";
February 1940:while taking a break between battles, "I stabbed on the back of an old man who was running away from a civilian house", and "the old man spit out blood and died";
December 1941:in Taiyuan, Shanxi, arrested two villagers, "stabbed with a Japanese sword on the chest of one of them and killed him" and "ordered my subordinates to kill" the other one;
Mid-February 1942:captured four villagers in a cave on the back hills of Xinzhuang Village, Taigu County, "I raped a woman aged 22 or 23 among them in my room, and another 27-year-old woman was gang-raped by two or three of my subordinates". The two men were interrogated with torture and said nothing, so one of them was killed;
Mid-February 1942:in a village to the southeast of Motianling, "assaulted a hospital of the Eighth Route Army on its way of evacuating; arrested 5 patients in a civilian house", after interrogating with torture two of them, "I killed them with a Japanese sword by myself";
Late February 1942:"covered up for about 10 surgeon senior captains from the Headquarters Dispensary of the Battalion to spread typhoid and cholera bacteria", "in the process, my Platoon worked together with the Company, occupying vantage points in Longmen Village, Guanchitang, Yanglezhuang and another two or three villages (names not clear) in Heshun County, where we covered the medical staff as they smeared bacteria on bowls, chopsticks, kitchen knives, rolling pins, cutting boards and tables in villagers' houses and threw bacteria into their water vats, wells and rivers nearby";
Late March 1942:"raped a female operator (aged around 25) of the Eighth Route Army, who was in custody, and then let the County Police gang rape her". In order to keep it secret from the Battalion Chief, the Company Commander "ordered me to kill the above-mentioned woman and two other captured operators of the Eighth Route Army and a businessman from Dayu Township, a total of 4 people";
Late May 1942:in a civilian house in the west of Jiangjunmu Village, "I personally killed with Japanese sword" 5 soldiers and cadres of the Eighth Route Army, who had been captured in the battle the day before;
June 1942:while camping in the streets of Shuizhi Township, Zhangde County, "I raped a 20-year-old girl in her home and ordered my subordinates to rape her mother";
July 1942:when stationing in Houjiaxiang, Taiyuan City, "when we conducted an inspection on bayoneting living targets … about 220 captives (mostly soldiers and cadres of the Eighth Route Army, students, and some soldiers of the anti-Japanese army) were brought here, one for each Japanese soldier to kill". "The active service education policy was: … to use live Chinese people as educational materials to test Japanese soldiers' courage and train them … all the instructors (including myself) prepared accordingly …… change the imaginary enemy into live targets in the stabbing course for inspection";
Around 2 August 1942:"ordered 70 new recruits of the machine gun units to … stab 70 captives (about 50 of them were women) as educational materials"; "during this inspection, all instructors, teaching assistants and about 340 new recruits killed a total of about 340 captives";
Late June 1943:"ordered Second Lieutenant Tanaka to kill with Japanese sword one villager, who was detained in the Company as an Eighth Route Army soldier suspect, in a little trench to the south of the village";
Late August 1944:in Qinxian County, "we captured one villager each from Nuanliu Village and Xiaohe Village"; "I ordered Captain Ma to shoot these two captives to death on the riverside to the west of Qinxian County".