Yamaguchi suggests that elements of the Japanese Army and a variety of hybrid civil-military organizations took the problem of COIN quite seriously from a strategic point of view, appreciating that the only way to victory in China was the establishment of a self-sustaining, pro-Japanese Chinese government.
However, the Japanese Army suffered from problems of focus and resources. Rather than concentrating on counter-insurgency operations, the Army needed to prepare for conventional operations against Chiang Kai Shek’s Nationalist Army, defensive operations in jungle and island theatres against British and American forces, and finally the long-anticipated Soviet invasion of Manchuria. These threats all posed radically different challenges, making training haphazard and incoherent. The Japanese also faced unity of effort challenges, with civilian and military agencies organized around pacification and institution building losing out in intra-agency battles against conventionally oriented officers.
Long story short, the history of Japanese operations in China was more complicated in process, if not in effect, than the “Kill All, Loot All, Destroy All” that has come to characterize the war*.
*Standard caveat: I trust that readers are bright enough to understand that this does not constitute an apology for the Japanese Imperial Army.