the Koe no Katachi series. Kazuki was Shoya Ishida's best friend in elementary school and he helped in the bullying of Shoko Nishimiya, but he never admitted to participating in it. Kazuki started bullying Shoya after the boy help pin the blame on him for Shoko being bullied. Due to this he still refused to be friends with Shoya even in high school as he told everyone in 7th grade to stay away from Shoya. When Shoya fell into a river after saving Shoko from committing suicide it was Kazui and Keisuke who brought him to the hospital, however he still refuses to reconcile with Shoya.