Yuzuru is Shouko's companion with hardships against the bullies or with her mother's forceful decision to Shouko. It seems she doesn't have a good relationship with her mother but bonds well with her grandmother. She has a hobby of taking pictures of the dead, with the objective of showing her sister how horrible death is, in order to encourage her sister to not kill herself.
Yuzuru, at first glance, has a boyish appearance. She has short black hair and blue eyes. She usually wears a hoodie and shorts and always has her camera with her.
Yuzuru is first introduced when Ishida looks for Nishimiya Shouko. Yuzuru claims to be Shouko's boyfriend to discourage Ishida from approaching her.
She cut her hair short to prevent her mother from cutting her sister's hair.
Yuzuru and Shouko have a sisterly relationship. Yuzuru is always looking out for Shouko and continuously tries to convince her not to commit suicide. Despite their fights Yuzuru loves Shouko to the point of cutting her own hair instead of letting Shouko cut hers. Yuzuru also (in the movie) tells Shouko to take her camera with her into the ferris wheel so she could spy on Ueno, later taking the footage to Ishida Shouya to show him what had really happened. Yuzuru is shown having a nightmare about Shouko committing suicide and wakes up. Another night she is reading Shouko's notebook when her Grandmother tells her not to read in the dark, taking her into dinning room where her Grandma (or Granny) tells her that she is worried about Yuzuru, saying that Yuzuru worries about Shouko so much that she doesn't care about herself. Yuzuru answers saying that her Grandmother is doing the same thing. Her Grandmother then tells her that it's different because she's doing it for herself.
At first, Yuzuru disliked Ishida, thinking that he was only trying to visit Shouko to amuse himself because she was deaf. Yuzuru lies to Ishida, telling him that she is Shouko's "boyfriend". Yuzuru even posts a picture of him jumping into the river online, causing him to get suspended for a week. Later on when Ishida is picking up his niece he finds Yuzuru unconscious in the park, appearing homeless, so Ishida takes "him" home to his house for the night. At midnight Yuzuru had a flashback of her and Shouko fighting. Yuzuru leaves in the middle of the night. As she's walking home Ishida catches up and walks her home. Yuzuru then tells Ishida that she is in fact Shouko's little 'sister'. Yuzuru then is constantly hanging out with Ishida, (especially in his room) and is involved in most of the drama with his friends. Ishida also helps Yuzuru with her schoolwork and walks her home on her Grandmothers funeral. He also claims that he worries about her when he sees her crying, and Yuzuru tells him that she is scared to go to the funeral before stepping away through the gate. Yuzuru also invites Ishida to the fireworks festival with their family.