Reiko, who married Koyakawa after turning 30 and having a child from a previous marriage. Her stepdaughter Akari also took to her well, creating a happy family like real parent and child. However, one day her husband did not come home. The next day, she consulted the police, but they did not take it seriously. As she was at her wits' end, she heard the doorbell ring. From that day on, a nightmare of days filled with torment began for the mother and daughter.
