This thesis investigates nuanced differences in the cultural dynamics between Japan and Taiwan. Prior cross-cultural comparison research often points out the cultural similarities in collectivism and individualism between the two countries due to their historical, geographic, and economic ties. Inspired by my personal experience and drawing from country-specific research on culture, religion, history, philosophy, and social movement, we found that the backgrounds of collectivism and individualism in Japan and Taiwan were not entirely the same as commonly assumed. Therefore, this study aims to elucidate the disparities in how collectivism and individualism were presented in these two countries and how they affect people’s perceptions and behaviors and even social media usage. To our knowledge, this is the first research that directly compares Japanese and Taiwanese attitudes toward the cultural shift on individualism and collectivism. To deepen our understanding of the topic, we conducted 12 in-depth interviews exploring individual perceptions and attitudes toward collectivism and individualism.. We found that both countries were still influenced by traditional collectivistic culture in several aspects, as classic literature suggests. However, more importantly, we discovered that Japanese and Taiwanese people react differently to the new-era of individualism and when it crashes with collectivism reacting to individualistic behaviors or expressions within the group. These differences can also be seen in the usage of social media. This research offers several theoretical and practical contributions. Firstly, it extends our knowledge of the cultural differences between Japan and Taiwan beyond Hofstede’s cultural comparison theory. Practically, this research provides insights for global companies and individuals alike helping them understand the cultures of Japan and Taiwan.