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.

(Source: Seishun Buta Yarou Wiki)