Tenkō
The prewar Japanese state considered Marxism to be a grave threat to Japan's "national essence" (国体, "kokutai"). The Peace Preservation Law, passed in 1925, empowered the Special Higher Police ("Tokubetsu Kōtō Keisatsu", abbreviated "Tokkō") to persecute communists, socialists, and other leftists by explicitly criminalizing criticism of the system of private property. Thus the year 1925 marked a new phase in which the "Tokkō" targeted not only incorrect action (actual crimes) but also incorrect thought or ideology, earning them the nickname, the . In 1927, a sub-bureau, the "Thought Section," was established within the Criminal Affairs Bureau of the  Special Higher Police in order to oversee the study and suppression of subversive ideologies. By 1933, ideological conversion had become the main means of enforcing the Peace Preservation Law, rather than judicial punishment. In order to elicit "tenkō" from prisoners suspected of ideological radicalism, the police employed physical torture, as well as physchological torture and familial pressure. One of the most consequential instances of "tenkō" came in June 1933, when Sano Manabu (1892—1953) and Nabeyama Sadachika (1901—1979), two leading figures in the Japan Communist Party, renounced their allegiance to the Comintern and the policy of violent revolution, and committed to  supporting only those forms of social change that might be consonant with Japan's "national essence." Their proclamation was followed by a wave of defections from the party, signaling the demise of the party organization, except in exile. In the postwar period, whether someone had succumbed to pressure (or torture) and committed "tenkō" became, among leftists, a sort of ideological litmus test and a form of stigma attached to the careers of left-leaning politicians, artists, and intellectuals active before and after the war. In the immediate aftermath of the war, many of these leftists attempted to atone for their  wartime "tenkō" by undertaking "self-reflection" ("hansei"), and often re-embracing Marxism and/or communism with even greater fervor than before. These figures were often spoken of as having undergone a "re-conversion" or "second "tenkō"" back to their original ideological stance. More broadly, the term "tenkō " also came to serve as a metonym for the collective experience of an entire generation of Japanese, first in turning toward support of militarism and imperialism before the war, and then again in turning toward supporting peace and democracy in the postwar.