In recent years, fandoms have expanded beyond national and regional boundaries thanks to the proliferation of social media. Social movements based on such connections are attracting attention because of fan activism. However, such fan activities also need to be carefully analyzed. While studying the autonomy and enjoyment of fan activism, Fandom Studies has criticized the possibility of fans being exploited by the cultural industry and mass media. This study is a case analysis based on Fandom Studies of the fan activities of K-pop fans using social media today. During the period when K-pop idols were unable to perform in Japan due to the covid-19 disaster, online interactive communication products were sold between the idols staying in South Korea and their fans living in Japan. The qualitative findings of this study revealed that while Japanese female fans enjoyed these online products, they tended not to continue purchasing them if they did not like them. By contrast, fans in the U.S. and Southeast Asia are enthusiastic about social movements aimed at elevating the K-pop image and solving social issues important to them. South Korean entertainment companies are also enthusiastic about social movements because efforts to resolve social issues are necessary for success in American show business. Japanese female fans were active in protecting K-pop idols, who were forced by their foreign fans to donate money and publicly endorse groups associated with social issues. The above attitude of valuing their own enjoyment and kindness to others probably serves an autonomous function in their fan behavior. It can be concluded that the above sensitive considerations are important in situations where people living in different everyday worlds use smartphones to enjoy and encounter diverse entertainment content.