二戰時期日本「轉向」的形成，旨在迫使左翼知識人放棄反國家主義立場，進而在思想、言行層面徹底地融入天皇國家制。事實上，促使思想轉變的動力，主要來自缔構近代國家體制的思想樞軸——國體。伴隨右翼勢力抬頭，政府為屏障國體，開始大肆取締亟欲變更國體的左翼知識人，將其指為「思想犯」，並在國家強制力驅使下，使其「轉向」擁戴日本國體。本文旨在探討戰時日本思想統制下「轉向」現象的形成，並以當時日本共產黨代表人物佐野學和鍋山貞親發表的「轉向」聲明——〈告共同被告同志書〉來造行剖析，藉以指認，本是作為「思想犯」的兩人，是如何在「轉向」後，將往昔主張的社會主義融入國體當中，從而在思想論述上成為戰爭行為的「協力者」。

The so-called “tenkō” (ideological or thought conversion) phenomenon which formed in wartime Japan (1931-1945) refers to how left-wing intellectuals were compelled to shift their anti-nationalist stance towards “Tennō (Emperor)-statism,” the driving force of which mainly originated of the national polity, or “kokutai.” During the early Shōwa period, following the rise of right-wing influence, the government attempted to safeguard “kokutai” by suppressing left-wing intellectuals who were striving to alter it. These intellectuals were deemed “shisō han” (thought criminals), and swayed by the power of the state authorities, shifted their attitudes to embrace “Tennō kokutai.” The aim of this study is to explore the formation of “tenkō,” which was enforced by the Japanese government during wartime, by analyzing the statement “A Letter to Our Fellow Defendants” by Sano Manabu (1892-1953) and Nabeyama Sadachika (1901-1979), two prominent communist intellectuals. This paper shall elucidate how these two leftists integrated their ideologies of communism into the “kokutai” following “tenkō,” thus becoming pro-war nationalists or even “collaborators.”