Yes I did know that, it was in Nanjing, two Jap officers were running about in a two man competition to behead as many Chinese as they could. The German Attache got to hear of it he did all that he could to bring it to a halt. I am not sure if this was before the war with Germany had started? The Chinese claim to have lost 100.000 people in Nanjing mostly to the Samurai sword and the bayonet.I have a couple of Photos taken by Dad of a Japanese Destroyer in Shanghai harbour as they had a Cantoonment in the international protectorate at the time. Perhaps you know this but the very first protest against Japanese attrocities came from the German attaché . Dad was doing the convoy runs from S to Peking before leaving in 1933.