Gender: Female
Age: 16-17
Birthday: October 23 (Scorpio)
Height: 5'1" (155 cm)
Occupation: Student
Affiliation: Minegahara High School, 2nd year, Science Club
Rio Futaba (双葉 理央, Futaba Rio) is one of the main characters of the Seishun Buta Yarou wa Bunny Girl Senpai no Yume wo Minai series, who is a second-year student at Minegahara High School. She had been in the same class as Sakuta and Yuuma during their first year and is the sole member of the Science Club.
She is a stoic and blunt girl who possesses substantial knowledge in science, including chemistry and quantum physics. She has a sharp sense of humor and is even more sarcastic and straightforward than Sakuta. Despite her stoic nature, Rio also shows various emotions such as love, as holds affection toward Yuuma, as well as anxiousness. She's also genuinely kind and loves her friends.
Rio is implied to have experienced a form of neglect. In addition, she has no siblings, which further proves that she chooses to be alone as this is her comfort zone that she unwillingly developed thanks to her lonely childhood. Although, this loneliness is what gave her the courage to approach Sakuta first when they were in the same class, as she saw him as an outcast just like her.
Before experiencing it herself, she was unwilling to believe the existence of Adolescence Syndrome, but she did acknowledge the abnormal phenomenon it induces and connects them with various scientific theories and principles.
At some point in time, Rio's feminine body parts had developed much earlier than her classmates. Once she discovered the way some boys were ogling her, she began to hate her body and felt like "a truly filthy being."
At some point during her time in the science club, she would come to be known for performing experiments that caused power outages as well as small fires.
Sometime before summer break, Rio created a social media account out of the desire to get someone's attention. She began posting lewd photos of herself and found salvation in receiving reactions, but in the end she was unable to get rid of her self-disgust. The resulting stress from her contradictory methods and results separated herself into two Rios: one that wanted attention and the other who could not forgive that her body was used to obtain it.
As a result of her insecurity over her body, Rio had split into two versions of herself on July 30; one who craved attention and one who hated the fact that her body was used to obtain that attention. After both versions were able to recognize and control their own feelings, Rio became one person again.
The second Rio Futaba behaves nearly identically to the original, but she has taken a hobby of posting risque photos on social media as a form of "self-mutilation" and to have an objective look on herself.
On July 30, the duplicate Rio began living at her home, which forced Rio to stay at a net café. Later that night, the original Rio was approached by Sakuta and Mai at the net cafe she was staying at. After informing them of her predicament, she took Sakuta's offer to stay at his apartment.
While taking a bath, she connected her problems with quantum teleportation by comparing her clone to one's perception of a blueprint with information on how to construct herself. Rio further theorized with Sakuta that the clone was a copy of her mind.
The following morning, the other Rio asked Sakuta to take care of her other self. Once Sakuta got home, he gave Rio her phone and informed her that he had deleted her social media account. However, when he was gone, Rio was disturbed to find a photo of her other self spending time with Sakuta and Yuuma, and went to sit alone at the school. Soon approached by Sakuta, she lamented that the other Rio was faring far better than herself, thus making her obsolete. Sakuta declared her statement completely wrong and announced they would meet up with Yuuma at Kugenuma-Kaigan station on August 19, before falling unconscious.
Once Sakuta recovered at the hospital, Rio was told that it was fine if she hated herself; in response, Rio remarked that Sakuta's blatant advice was somehow a relief. She asked Sakuta if she could go to the fireworks festival with them, but was directed to call and ask someone else. After calling her other self, she disappeared on the spot, having become one person again.
While watching the fireworks festival, on August 19, Rio confessed her feelings to Yuuma, but before he could reply, Rio claimed that she already knew the answer. She then told him to make up with his girlfriend, before wiping away her tears to watch the fireworks.
