Star Mirai Project: Utahime-hen

VTubers constantly upload content in pursuit of popularity, with some gaining fame through their singing. Ariel is a top idol in this space, so well-known that she has become a cultural figure, though her real identity remains unknown. A shocking announcement claims she may be dead, followed by the revelation of an audition to find her replacement. Nanane, a casual fan, applies out of curiosity, hoping to meet her favorite idol. She soon learns the audition is a deadly competition where only one contestant will survive and become the next idol. The event is called the "Shoujo Circus."