The most popular streamer U-san, specializing in investigations, tries to identify a serial killer who chooses as his victims beautiful girls in red. To understand the killer's train of thought, U-san decides, together with another streamer named Matilda, to recreate the scene of the latest murder. The broadcast attracts a large audience, but Matilda takes the initiative, and U-san drops from the top of the popularity charts. When, after some time, it becomes clear that Matilda has disappeared, the man sets off to search for her.