Struggling detective Satoru Kido is lured to a remote island by a mysterious letter requesting his help to find a missing family heirloom: a rare ruby ring known as "the blood of a phoenix." Upon arriving at the Nakakouji mansion, Kido encounters the unstable mistress Ayano and the timid maid Nozomi. As he discovers hidden passages and navigates the mansion's erotic and psychological tensions, he realizes the case is far more complex than a simple missing item search.
Detective Satoru Kido discovers a shocking connection to the Nakakouji mansion, realizing he is the rightful successor to the family fortune. As Ayano's psychological instability leads her to mistake Kido for her father, greed and betrayal erupt among the mansion's inhabitants. The mystery of the missing jewel is revealed as a ruse, and the cycle of obsession culminates in a devastating fire that consumes the estate and all its secrets.