We juxtapose major historical developments in science communication and public engagement in Japan and the UK, toward demonstrating differences in not only how the “public” is defined but also why its presence is considered important. Many stories have been told about the trajectory of how science communication and public engagement policy have developed in the UK, the EU, the US, and Australia, where largely comparable events have unfolded. In contrast, the Japanese government’s recent experiences are much less well known internationally, and do not follow the same pattern of intellectual movements. We highlight these contrasts to challenge and open up dominant Western narratives, toward making more space for considering how discussions on science communication and public engagement have evolved in different ways in diverse settings. Simultaneously, we point to idiosyncrasies in the UK experience that may not always be observed as such. In so doing, we demonstrate that connections—or, as it may be, the absence of connections—between RRI and science communication and public engagement cannot be taken for granted and must be addressed in specific contexts.