How can potential public backlash to Japan's rapidly expanding immigration be minimized? We investigated whether immigration can gain and maintain public support when voters understand that it can help address other nationally important issues, such as Japan’s demographic challenges. Building on our previous research, we conducted a large-scale survey experiment in Japan with two main objectives: (1) to measure voters’ perceived importance of immigration and population decline alongside their specific policy preferences, and (2) to test whether these attitudes change when voters are exposed to information about the national benefits of various immigration and population policies. Since a significant portion of Japanese citizens had not yet formed strong opinions on immigration, Japan served as an ideal setting to examine attitude formation and change. Our preliminary results show that when voters were presented with information highlighting how immigration or population policies could alleviate pressing demographic issues, there was a notable increase in support for these policies. Specifically, we observed that voters’ preferences and perceived importance of specific subissues, such as immigration admission numbers, were positively influenced by the information provided. However, when counter-information about possible negative impacts of immigration or population growth was introduced, these positive effects were somewhat mitigated but not entirely reversed. Overall, our findings suggest that informing the public about the benefits of immigration in addressing demographic challenges can positively influence attitudes, even in culturally conservative contexts where significant immigration has long been considered to be impossible.