Shinrei Tantei Yakumo (心霊探偵 八雲, lit. "Psychic Detective Yakumo") is a novel by Manabu Kaminaga published in Nihon Bungeisha with illustrations by Katoh Akatsuki and later in Kadokawa Bunko with cover illustrations by Yasushi Suzuki. The book has been adapted into two manga series', an anime, a live-action drama series and a stage play.
In order to help a friend possessed by a spirit, Ozawa Haruka knocks on the door of her university's movie research association. There she meets Saitou Yakumo, a rude, unkempt young man with a red left eye, who is said to have spiritual powers. At first Haruka is skeptical, but she comes to believe him when he conveys messages from her older sister, who died when she was a child. Together, they work to shed light on the terrifying events happening at their university. But this is only the prologue of what's to come.