Six Hololive Vtubers and a song they performed arrived in Taiko no Tatsujin: Rhythm Festival. As a Hololive Golden Game Week reward, Houshou Marine, Kazama Iroha, Momosuzu Nene, Shiranui Flare, Shirogane Noel, and Takane Lui all appear in-game. So does their song, “Roppon no Bara to Sai no Uta.” However, only subscribers get to access the content and its associated accessories. While the activity to “earn” this was a Hololive Japan one, it is appearing in the game worldwide.
Here’s the announcement that appears in-game revealing the event. It points out “Roppon no Bara to Sai no Uta” is a Taiko Music Pass song. (That service costs $3.99 for a 30-day pass.) If you play the song, you can get puchi characters of Flare, Kazama, Lui, Marine, Nene, and Noel. These can be equipped alongside your avatar.
The official Japanese YouTube channel uploaded a music video to go along with the crossover. It features the song people will be able to play in-game. While there are Taiko no Tatsujin references, such as a Don statue and a hint of gameplay footage, it primarily focuses on the Hololive Vtubers.
Taiko no Tatsujin: Rhythm Festival is available for the Nintendo Switch, and the event featuring Hololive Vtubers is live.