The purge was planned before Japanese troops landed in Singapore. The military government section of the 25th Army had already drawn up a plan entitled "Implementation Guideline for Manipulating Overseas Chinese" on or around 28 December 1941.() This guideline stated that anyone who failed to obey or co-operate with the occupation authorities should be eliminated. It is clear that the headquarters of the 25th Army had decided on a harsh policy toward the Chinese population of Singapore and Malaya from the beginning of the war. According to Onishi Satoru,() the Kempeitai officer in charge of the Jalan Besar screening centre, Kempeitai commander Oishi Masayuki was instructed by the chief of staff, Suzuki Sosaku, at Keluang, Johor, to prepare for a purge following the capture of Singapore. Although the exact date of this instruction is not known, the Army headquarters was stationed in Keluang from 28 January to 4 February 1942...
Clearly, then, the Singapore Massacre was not the conduct of a few evil people, but was consistent with approaches honed and applied in the course of a long period of Japanese aggression against China and subsequently applied to other Asian countries. To sum up the points developed above, the Japanese military, in particular the 25th Army, made use of the purge to remove prospective anti-Japanese elements and to threaten local Chinese and others to swiftly impose military administration.〔(【引用サイトリンク】title=The Battle of Singapore, the Massacre of Chinese and Understanding of the Issue in Postwar Japan )〕