The mysterious transfer student Sayoko Hoshi hides a dark secret: she is actually Mandala, the daughter of the great demon king who once ruled an underground realm over a century ago. Her true form is a yokai princess from a hidden hell beneath Japan, a place where constant earthquakes shaped a bizarre, isolated species. Mandala was entrusted with two all-seeing crystal eyes and sent to the surface world to rescue her dying clan from invading western demons. But during her mission she lost one of the crystal eyes, and for a hundred years she has wandered the human world in search of it, knowing that without it her clan cannot be revived.

Her quest draws the attention of a monstrous adversary known as the Bloodsucking Crow, a creature that seeks the stolen eye for its own purposes. As Sayoko navigates human society, her secret identity puts her in constant danger. The narrative unfolds through a series of escalating confrontations: the revelation of Sayoko's true nature, the pursuit of the lost eye, and a bloody clash with the Bloodsucking Crow. The search leads to a catastrophic finale where Mandala's long hunt finally reaches its end, and the fate of her entire hellish lineage hangs in the balance. The story blends folk horror with action, set against the grim backdrop of a decaying underworld and a human world oblivious to the ancient war beneath its feet.