After waking in a mysterious world, the protagonist finds himself inhabiting the body of someone named Sakabe, with no memory of how he got there. He navigates a world filled with humans, demons, and demi-humans, where power is governed by Arcana. Struggling with his identity, he encounters allies like Aria and Juna, though their intentions remain unclear. As he unravels cryptic messages and confronts ominous entities, he realizes his existence is manipulated by higher forces. Determined to survive and uncover the truth about Sakabe and this world, he balances wit, courage, and his own humanity in the face of impending doom.