With a case of social anxiety bordering on agoraphobia, combined with the trauma of losing her mother Wakaba Isshiki, Futaba is strongly discomfited by going outside. When the protagonist first meets her, she is a hikikomori who does not attend school and almost never leaves her room. She communicates with the world remotely via the Internet, and her adoptive father Sojiro Sakura enables her lifestyle out of guilt that he could not protect her from trauma. Having disconnected herself from humanity and the world beyond her apartment, Futaba is lonely, lives without passion and enthusiasm, suffers from suicidal depression, and questions the point in her living. Futaba begins to change after meeting the protagonist and the other Phantom Thieves, opening up to them more and becoming more relaxed around them. Once she's truly comfortable around others, she shows her childish side and likes teasing her friends, particularly Ryuji Sakamoto, Yusuke Kitagawa and Morgana, and sometimes Makoto Niijima as well. Although she still has occasional anxiety and odd habits, she comes off as bright, playful and cheerful when with her newfound friends. However, due to being socially inept, Futaba is often extremely blunt, to the point that she seems to have no concept of tactfulness.

She also has a rather ruthless side to her; not only does she have zero qualms with hacking, to the point of bugging the protagonist's phone so she can keep an eye on them during their trip to Hawaii but she cares little for the group's main goal of reforming society; she only wants to find out the truth behind her mother's death, and get revenge on the ones responsible, which she admits is an extremely personal reason. Makoto even states at one point that she's glad she's on their side, with fear of what she'd do if she was their enemy. As she is actually the real Medjed, her hacking skills had been implied to be of worldwide fame as a book about it can be purchased which states that Medjed is known worldwide for its activities. However, this identity remains anonymous to the public.

Set to appear in;

- Dark Sun

- Stars and Ours

- A Magical Valentine's Day

To have an idea on how Futaba should sound, this should help: https://www.youtube.com/watch?v=cE1rygBVVnY