Seisai

A murder occurs at Nankai Academy, where popular teacher Professor Yuko is pushed from a rooftop. Her death leaves her students, particularly four boys named Masayoshi, Daisuke, Mitsuru, and Shinya, filled with anger and a desire for the truth. They find a key clue in her planner, which is marked with the names of seven girls on the night of her death. The boys launch an investigation, resorting to methods including rape, manipulation, and torture to uncover details. As their search progresses, they find themselves increasingly consumed by their own dark impulses. The process of assembling the puzzle proves difficult, raising the question of whether they will ultimately discover the truth behind Yuko's death.