Natsumi Aihara is a police investigator who appears in the 1999 television drama Rasen, the sequel to Ring: The Final Chapter. She was originally a student of Mitsuo Ando, a pathologist, and later becomes his ally in confronting the supernatural curse linked to Sadako Yamamura. Her background in law enforcement provides her with investigative skills, access to criminal records, and a practical approach to danger. She is determined, resourceful, and willing to face the unknown, driven by a desire to stop the spread of the curse and protect the innocent. Her role in the story is to assist Ando in tracking down clues about Sadako's origins and to combat the threat posed by the cursed videotape. Key relationships include her former teacher Ando, with whom she shares a bond of trust and collaboration, and Mai Takano, a target of Sadako. Over the course of the series, Natsumi develops from a student into a capable and courageous investigator, growing more resolute as she confronts horror beyond normal experience. Notable abilities include her deductive reasoning, persistence in uncovering hidden information, and the courage to face lethal supernatural forces.