The title's "Kurokage" (meaning "Black Shadow") is reflected in the work's lighting.

It sat hunched upon the rusted pipe three floors below, shoulder blades feathered in a silver so thin it might be smoke. At first glance it could have been a child with a shawl, but the shawl trembled as if remembering wind. Its head tilted toward the alley where a pair of figures moved with practiced theft. Ryu considered descending. He thought instead of the ledger tucked beneath his jacket: a small book where names, dates, and a single sentence for each angel had been recorded, written in his same spare hand.

Unlike traditional depictions of angels with soft, ethereal robes, Kurokage’s angels are futuristic. They often feature mechanical halos, technological wings (sometimes made of energy or metal), and gear that blends the divine with the cybernetic.

The identity behind remains unknown. Interviews have never been given. Some speculate it is a former game designer from the Silent Hill era. Others believe it is a collective of writers running a transmedia experiment. The most radical theory suggests that "Ryu Kurokage" is an AI trained on lost Japanese horror visual novels and German expressionist poetry, with the ".19" being the model version.