An unauthorized artist who Yayoi met when playing on a stage.

Spoiler

In Yayois background episode it is shown that the two shared a deep relationship and when Yayoi was locked up as a latent criminal, Rina started an antisocial movement that vandalized street scanners. When Yayoi confronted Rina when she was joining the inspectors investigating the vandalism, Rina walks away into the tunnels with the rest of the gang. It is unclear if she is caught.