Rio Miyaichi

Rio is two years older than Kurosu and lives in the apartment adjacent to him. Unbeknownst to her there is a hole in the wall between their two apartments that Kurosu has been watching her from.

She enjoys cooking for her neighbor, Kurosu. Oh, and also murdering various males that she lures to her apartment with her weapon of choice, a box cutter.

She goes to college, but is a loner - acting very antisocial in order to remain distant from the other students.

After consummating her marriage with Kurosu she was shot in the stomach by police officer Jun, who had long been suspecting her of being a serial killer.

After two years she awakes from a coma. She has amnesia from the trauma.