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 first introduced, she is a hikikomori who does not attend school and almost never leaves her room. 

Futaba begins to change after meeting Joker 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.