Isaku Ito works as the school gardener at Orin Gakuen, shadowed by unrelenting negative rumors. He presents as a senior-aged male with black eyes and neck-length black hair. As the central antagonist, he imprisons students—including Kenta and classmates—inside a locked, abandoned school building. His objective focuses on capturing victims across the structure, with particular emphasis on targeting female students. After abduction, he records non-consensual encounters on video tapes; these may be discovered by the protagonist during escape attempts and document assaults between Isaku and his victims. Players must locate keys to unlock stairwell doors across floors while evading his captures, critical to survival. Escaping remains feasible even if some party members are abducted, though optimal endings become unattainable. His presence maintains constant tension as he stalks the corridors, enforcing the narrative’s survival-horror dynamic.