In November 2018, virtual pop band K/DA, with the use of holograms and actual K-pop girl group members, performed its debut album titled "POP/STARS" at the opening ceremony of the League of Legends S8 final, hosted by Riot Games. The fan culture that exists for real singers adapts itself to virtual bands, and K/DA, consisting of virtual characters, encouraging the production of user created content (UCC). However, this form of UCC is different from the most common one, meaning that this type of band generates another way of consuming content. Therefore, this study examines how K/DA's digital characters are transformed and reproduced by UCC and how the original producers' content differs from them. Firstly, the development of this study considers the open characteristics of UCC, such as user type, created motivation, created process, content type and sharing method. In the second part, the virtual idol Hatsune Miku and virtual band Pentakill will be analysed to understand UCC. Thirdly, K/DA will be analyzed as a case study based on three factors: created motivation, content type and sharing method. In this manner, this study aims to explain how UCC for virtual bands reproduce and consume original content and expand their commercial value.