This study presents the extent of exposure to shared news via social media in Japan and its effects to Political Efficacy and Common Knowledge. The online survey results showed that only 14.9% to 22.3% of the respondents had accessed shared news, while 95.2% had watched television news, and 72.4% had read newspapers. Regression analyses indicated that exposure to the shared news via LINE was positively associated with Political Estrangement and negatively associated with Common Knowledge. This result suggests that the social media which promote communication on close relationships could reduce the diversity of news exposed to people.
