Public opinion has become an increasingly consequential force in shaping international relations, with perceptions of China standing at the center of debates across East Asia. Notably, while youth in South Korea, Taiwan, and Malaysia tend to hold more negative views of China than their elders, Japan presents a reverse pattern: younger generations display higher affinity toward China compared to older generations. This paper investigates the sources of this divergence using 2023 survey data from the Sasakawa Peace Foundation. Building on generational cohort theory and collective memory, the paper redefines Japanese generational groupings and applies regression analysis to identify the key drivers of affinity toward China. The results show that younger Japanese cohorts, though highly curious and actively consuming China-related information, exhibit limited knowledge of China’s political and social structures and display weaker attentiveness to political dimensions. By contrast, older cohorts anchor their perceptions in political memory and bilateral disputes, leading to increasingly entrenched disillusionment. These findings suggest that Japan’s generational gap reflects internal variations in cognitive socialization rather than an overall warming of bilateral relations, underscoring the need to closely monitor evolving youth perceptions in the years ahead.