Metaverse services are being extensively used in the K-pop entertainment industry. The four types of Metaverse technologies (augmented reality, lifelogging, mirror worlds, and virtual worlds) help K-pop fandom be actively involved in participatory activities such as affiliations, expressions, collaborative problem-solving, and circulations. This paper reports on Metaverse usage practices, success factors, and most effective a!ordances by drawing from a case study conducted on BTS, currently the most popular K-pop band. We investigate four examples of BTS practices– We verse, BTS World, Twitter, and Fortnite – as Metaverse platforms. From the sepractices, we identify a set of key success factors in increasing and deepening BTSfan culture, which are affordances for alliance, users’ expressions, spread ability, and reflection of the real world. We conclude by proposing design strategies to optimize the satisfaction of Metaverse fandom.