When the shadow of Victoria meets the neon of Cyber Tokyo, two completely different women hold each other's bloody hands in the rainy night.
Tsukishima Rei is the ace of the Metropolitan Police Department's Special Technology Crime Countermeasures Room. The mechanical prosthetic eye in her left eye can see through all data lies, but cannot see through the warmth of people's hearts. Scarlet Night Rothschild is the descendant of an ancient European supernatural family. The silver key on his chest can open the mysterious door, but it cannot open the curse he carries.
The two were supposed to be walking in parallel in their own worlds, until the "Mechanical Heart Serial Murder Case" forcibly intertwined them - seven high-tech company executives were elegantly eviscerated on a rainy night in Tokyo, their hearts replaced with sophisticated clockwork devices, and the gears were engraved with the emblem of a crescent moon entwined with thorns.
Tsukishima believes in scientific evidence, and Feiye knows ancient mantras. Tsukishima relies on procedures and logic, while Hiye believes in intuition and mystery. They are gears and spells, reason and fantasy, modern Tokyo and the ghosts of yesterday.
But the real murderer is neither a pure scientific madman nor a traditional black magician. Hidden under the blood moon are the consequences of the "artificial god" experiment a hundred years ago, the sins buried by the supernatural family and the technological organization, and a crazy plan that attempts to replace the soul with machinery and rewrite reality with code.
As for Tsukishima and Feiye, one of them has the blood of the experimental product flowing, and the other carries the fate of a caretaker. To prevent this disaster, they must learn to make the gears resonate with the spell - even if that means one of them may become a sacrifice on the altar.
Purpose: In an alienated world where machines and mantras intertwine, explore human nature, free will and identity.