One day a mysterious woman clad in mourning dress appears in the office of Katsuya Furuyagi, a private investigator who possesses a unique ability to journey into the minds of people. The woman has a strange request that makes Furuyagi doubt her sanity. For generations, a beautiful doll has been in the possession of her family; however, recently it has disappeared, and the woman is convinced the culprit is the devil himself. Furuyagi travels to the countryside where he begins to investigate this unusual mystery, determined to find out the truth.

Orgel plays similarly to previous installment in the Psychic Detective series. The bulk of the game is occupied by conversations with characters, which often involve talking about various topics, gathering information. There are no puzzles, but pieces of evidence can be collected, stored, and viewed as inventory items. The interaction with the game world is menu-based.