What the claim actually is

This archive does not claim that Kokushi Corporation formally existed during WWII.

The narrower allegation is that personnel, terminology, filing systems or research practices survived the war and entered postwar medical, corporate or academic networks from which Kokushi later recruited.

A numbering format later found in Human Engineering records appears in copies of wartime medical and behavioural research material.

Authentication of the wartime copy remains disputed.

Nazi experimentation links

Researchers have also pointed to the postwar circulation of German and Japanese military medical literature, including material produced through unethical human experimentation.

No document here proves a direct Kokushi–Nazi institutional connection.

The credible historical question is whether later researchers associated with Kokushi cited, inherited or normalised methods that originated in wartime experimentation programmes.