Synopsis: Zerozaki Soushiki no Ningen Shiken

Iori, a high school student without direction and a tendency to avoid her problems, is attacked by a group of eerie individuals with lifeless eyes on her way to school. Fortunately, a mysterious long-haired man comes to her rescue. Later that day, her classmate Jion falls prey to the same homicidal influence, but Iori surprisingly manages to defend herself against his violent assault. The enigmatic Zerozaki Soushiki reappears and invites Iori to be his younger sister, plunging her into a perilous situation with challenges to conquer.