Anyone who does intelligence work knows that if you want to get evidence, the easiest way is to open a hole from the inside. Liu Nina is an agent trained by the Japanese secret service, and the more easily gain the trust of these people. ,The purpose of the Japanese government in carrying out this kind of behavior is to publicize the strength of the Japanese army and the victories of the Japanese army in Southeast Asia to the Chinese people, and at the same time it is necessary to encourage the trust of the puppet Vuong government.