Rikako Ouryou

She was introduced in episode 6 as a pretty, intelligent, and highly admired student of Oso Girl's Academy who is the head of the school's art club. Her talent for painting is impeccable. However, behind her sweet facade is a psychopath whose obsession is killing her fellow schoolmates and using their bodies to construct grotesque works of art and have them displayed in the middle of the city underneath a Holographic Illumination. It is unclear as to what is her relationship with Makishima is, but it is hinted that he is helping her carry out her psychopathic obsession. Her father is confined in a hospital in a vegetative state. (Source: Otaku-streamers forum)