The story of a 15-year-old junior high school student. Hiroshi transfers from a private school to a public one in order to emulate the delinquents in his manga books. On his first day, he's challenged by the school's most notorious delinquent, Iguchi Tatsuya, and ends up beaten and caught by a detective. He finally gains recognition by winning a one-on-one fight against a student from another school, and joins the ranks of delinquents, leading a life of fighting against other schools.
Every year, Nana Sasaki and her former classmates hold a reunion of their high school music club. This year, the reunion is being held online. However, one of them, Ayumi, doesn't show up. When the others voice their concern, Yuki and Suzu reluctantly tell them about the Samejima Incident, an urban legend which circulated on the internet 20 years earlier. Those who find the truth about it become cursed and die. As Nana and the others start to panic, the real horror begins.