"Spider and Tulip" (1943) and "Momotaro, Sacred Sailors" (1945) are considered masterpieces of the Asia-Pacific War period. As research on both works increases, their political overtones have been highlighted in various forms. In contrast, studies have not discussed lip syncing that is evident in these works. Therefore, this paper examines two questions by focusing on Kenzo Masaoka who was involved in the production of both works. First, is understanding how lip syncing was introduced. American animators such as the Fleischer brothers influenced Masaoka before the War. Second, is comprehending what lip syncing in "Spider and Tulip" and "Sacred Sailors" represents, for instance strong political nature such as the construction of the "Greater East Asia Co-prosperity Sphere." By considering these questions, we argue that before the war Masaoka was attempting to counter imported American animation while imitating their production method. Moreover, during the Asia-Pacific War when American works were prohibited from being screened, Masaoka was expression opposing America by producing highly artistic animation. We analyze how his way of thinking is different from Mitsuyo Seo’s way of thinking - Seo is the director of "Momotaro, Sacred Sailors."