Japan's unique political landscape raises an intriguing question: Do prime minister cues influence voter policy preferences more than party cues? This study investigates cue utilization effectiveness using a survey experiment. Previous research found single-party cues ineffective, but this paper examines whether leader cues could provide stronger guidance.

The experiment tested two main hypotheses. First, do opposition supporters react differently to prime minister approval compared to ideological cues from parties? Second, does signaling multiple-party support enhance policy evaluation in Japanese voters?

Survey respondents showed distinct patterns based on their partisan identity. For incumbent party supporters, prime minister cues had minimal impact - consistent with prior findings about single-party cues' ineffectiveness. However, opposition supporters reacted strongly when policies appeared backed by the premier's personal approval.

Interestingly, these leader cues also demonstrated stronger influence than information about ideological parties endorsing a policy. This suggests that multiple-party support (as opposed to single-party) may enhance cue informativeness in multiparty systems like Japan.

The findings highlight an important distinction between leadership and party dynamics in Japanese electoral politics. The results offer insights into how voter heuristics operate differently for supporters of different parties, which has significant implications for political communication strategies.