Shinrei Tantei Yakumo tells a story of a college student, Saitou Yakumo, who was born with different eye colors. His red left eye gives him the special ability to see ghosts and spirits. He believes ghosts and spirits are bound to earth because of a certain 'cause' and simply eliminating that 'cause' will let those spirits will rest in peace. Being asked for help by Ozawa Haruka, they begin the investigation together.