Part 4/8:
As it turns out, Kasai has been falsely accused of being a bully. During flashbacks, viewers witness that she neither bullied nor participated in the torment of Shino, but stood by as an observer. This revelation ignites animosity towards Kasai from the rest of the class, quickly ostracizing her. Shino's subtle manipulations further entrench the divide, and Kasai is left to endure a barrage of subtle harassment.
Kasai faces humiliation daily as the bullying intensifies. The school becomes a hostile environment where Shino and Yuria's gang revel in their cruelty. When Kasai attempts to stand up for herself, her actions instead fuel further disrespect from her peers.