Ijime 0 no Gakkou

With excellent teachers and a perfect monitoring system, this high school promised absolutely zero bullying. Seiwa, a first-year student there, meets a former classmate, Shijo-san, who was bullied in junior high school. The two gradually become friends in this bully-free school. One day, however, Seiwa learns that Shijo-san was bullied, and then he sees her jumping off the rooftop. A shocking “zero bullying” mystery! (Source: Yanmaga, translated)