Fujita Anju finds herself trapped in a mysterious facility with a handful of bewildered strangers, all suffering from fragmented memories and a creeping sense of dread. Their unease crystallizes when a peculiar cubic entity called Dokuroku emerges and announces its sinister purpose: to infiltrate the Prisms embedded in their ears—neural implants that every human receives at birth—to excavate buried memories and locate a powerful, reality-bending artifact concealed somewhere within their forgotten pasts. As the group grapples with their amnesia and Dokuroku's intrusion, they must piece together who they are and what they're hiding before the creature unlocks secrets that could reshape the world itself.