This article examines trans-scripting in transnational, multilingual fandom on Sina Weibo, the largest Chinese microblogging site. Taking one of the most popular Korean pop music (K-pop) bands named BTS as a case study, 741 instances of trans-scripting were manually selected from a total of 18,243 comments under the official Weibo account of the largest BTS fan club in China. Combining online observation and corpus-based analysis, our study draws on the notions of engaged audience and affinity space to reveal how multiple patterns of trans-scripting are heavily mobilized by K-pop fans in translingual idol naming, the transcultural maintenance of fan-idol kinship, and the intertextual confirmation of shared media consumption experiences. We argue that trans-scripting is an under-explored linguistic strategy used by transnational pop-culture fans, providing an analytical lens for research on fan identity and fan-communal membership. Theoretically, trans-scripting can serve as a useful lens to analyze networked multilingual fandom.