Introduction
Rio is the student council president of Millennium. Cold and calculating, she cares more about objective facts than emotions. She is at odds with Himari due to their contrasting personalities.

Rio has always been unsociable and rather scrupulous. She never lets emotions change her mind and always sticks to the facts. Because of this, a lot of students find Rio to be terrifying, but Rio doesn't let their opinions into her head. She is a quiet erotica and is busy all day.