The Tosei Ha, Japanese for Control Group faction, was a faction of the Imperial Japanese Army which formed in the aftermath of the invasion of Manchuria. Like its rival faction, the Kodo Ha, it supported further expansion of the Japanese Empire into Manchuria. However, the Tosei Ha viewed China as Japan's main enemy, while the Kodo Ha felt the Soviet Union was a greater threat. Further differentiating it from its more militant rivals, the Tosei Ha sought to adhere to strict guidelines and seek more formal rules of engagement, achieving its aims while working within the political system.
In February 1936, the Japanese First Infantry Division revolted in Tokyo in support of the Kodo Ha, killing many government ministers and civil servants. The mutiny was eventually put down by imperial order. The Tosei Ha, at least ostensibly, maintained control of the army. However, Woo felt that the Tosei Ha's victory over the Kodo Ha was not total, as did some members of the Tosei Ha, reflected by their subsequent change of policy. Nevertheless, Japan opened hostilities with China, not the Soviet Union, in July 1937. (PROSE: The Shadow of Weng-Chiang)