According to the written confession of Ken Yuasa on 20 November 1954, he was born in Tokyo Prefecture, Japan in 1916. He joined the Japanese War of Aggression against China in January 1942.

Major offences:

In late March 1942: In Lu’an Army Hospital in Shanxi Province, “carried out vivisection demonstration” on the captives, “forced down a large dose of anesthetic into the live body of a captive in order to check the symptoms when the victim was alive or dead”; “I practiced ‘tracheotomy’ on another captive”; after the experiment, “I, together with another military surgeon, strangulated him with a belt”.

On 14 April 1942: In the First Army Engineering Team (POW internment camp) in Taiyuan, Shanxi Province, “let about 30 military surgeons living in all army hospitals and field hospitals in Shanxi Province perform surgical demonstrations on live bodies of four captives”.

In late August 1942: In the dissection room of Lu’an Army Hospital, over ten surgeons “conducted live-body operations on and killed” two captives; “I cut open the trachea of a captive with field tracheotomy apparatus for practice”; “another captive was subject to intravenous injection of anesthetic and chloroform, in order to test how these drugs can cause people to choke to death”.

In late March 1943: In Lu’an Army Hospital, over ten surgeons performed “operation demonstrations by killing” two captives.

From February 1942 to November 1943: In Lu’an Army Hospital, “got the inpatients’ fresh bacteria of typhoid, Type-A paratyphoid and Type-B paratyphoid and gave them to the Field Epidemic Prevention and Water Supply Department of the 36th Division stationed in the south side of Lu’an City”. “It was provided regularly at least four times a year, and I supplied this unit with bacterin for bacteria warfare as many as eight times.”

In early April 1944: In Lu’an Army Hospital, used two captives as “materials for operation practice” for over 10 military surgeons.

In late September 1944: In Lu’an Army Hospital, two captives were sent to the hospital under escort; “I provided one of the them as material for operation demonstration to about 10 military surgeons of the dissection room. The other one was given to the Hospital Director, who beheaded the captive”.

In late January 1945: In Lu’an Army Hospital, “provided” a captive “as material for live-body operation demonstration to the military surgeons of the dissection room of the hospital and about ten military surgeons of the 14th Independent Infantry Brigade”.

In mid-March 1945: In Lu’an Army hospital, about 10 military surgeons used two captives in custody as “materials for operation demonstration in the dissection room”.