Shinrei Tantei Yakumo, originally a novel by Kaminaga Manabu, follows the tale of Saitou Yakumo, a university student with heterochromia - a red left eye that grants him the power to perceive ghosts and apparitions. Yakumo is convinced that these spirits are tethered to the mortal realm by a particular "trigger" that, if removed, will enable them to find solace. When Ozawa Haruka approaches him for aid, the two partner up in their inquiry.