The radical militarists that took over the Japanese government had a particularly brutal interpretation of Bushido, and were certainly not above using violence, up to and including murder, to obtain and secure power.
The Bushido Code don't exist.
There is no reference text about what Bushido is, no single list of maxims or sentences defining Bushido, no books to serve as litteral references.
And if you know a book that present Bushido as a unified Code, I will be glad if you give me some references. I read at least a hundred book about Japan History and military traditions and don't find any reference text about Bushido.
But I have read books stating that Bushido should include Compassion, among Courage, Courtesy, Loyalty, Duty, Honesty, Justice and Honor as core values.
I don't think there is a single text of Bushido that imply that you have the right to use prisoners as target practice, as slaves, and that you have the right to torture them or even eat them.
Loyalty and Honor are core values of Bushido, and the Japanese don't respect these values when they don't respect the international agreements about treating POWs, they signed forty of fifty years before and that they respected during the Russo-Japanese War and WW1.
Bushido had nothing to do with the horrors commited by the Japanese during the China War or during WW2. Something snaped in the collective minds of Japan military after WW1.