Nishimiya’s younger sister who is currently a middle school student. She cut her hair short so their mother would not cut Nishimiya’s and has kept it that way ever since; due to this, she is often mistaken for a boy, with Ishida even thinking that she is Nishimiya’s boyfriend at first.
Yuzuru is extremely protective of her big sister and has a deep hatred of all the people who ever bullied her, in particular Ishida; however, upon learning that Ishida has changed, she mellows down, accepts, and even encourages him to go out with her sister, though she is frustrated of their reluctance to do anything about their feelings and never moving past their relationship as friends. Yuzuru often bunks off school to take photos of dead animals and insects, which causes her and her mother to not get along.
It is later revealed that she only took these photos so that when her sister saw them she would see how horrible death is and not try to kill herself.