His younger brother was Imamura Hosaku, an officer in the Kwantung Army who fought in the Chinese Civil War as a mercenary for the Kuomintang.

As his fleet approached Java, his transport, the Shinshu (Ryujo) Maru, was sunk by torpedoes, probably by friendly fire, in the Battle of Sunda Strait and he was forced to swim to shore.

However, his policies won much support from the population (particularly in Java, where he was based) and helped to mildly reduce the difficulties of the Japanese military occupation.

One infamous example, called the "pig-basket atrocity", occurred when prisoners captured in eastern Java were transported in bamboo baskets used for pigs.

[6] Imamura was charged with "unlawfully [disregarding and failing] to discharge his duty ... to control the members of his command, whereby they committed brutal atrocities and other high crimes".

He considered his imprisonment too light with respect to his responsibility for the crimes of his subordinates, so he had a replica of the prison built in his garden, and he stayed there until his death in 1968.