There is an unusual Grim Reaper.

This Grim Reaper has a penchant for solving mysteries, dedicating its life to resolving cold cases. It seeks out souls whose wishes could not be granted and summons them to its abode.

It is a library where the memories of countless deceased are preserved as books, and also a pseudo-detective agency for the Grim Reaper to unravel mysteries.

Utilizing the memories of the deceased and its divine power, the Grim Reaper creates a simulated stage, transforming an unsolved case into a single book. It then involves the souls, enjoying the puzzle-solving from their perspective.

Should they fail the puzzle, the soul is annihilated. Even success brings no revival for the deceased, nor does it alter facts. Only the truth becomes clear.

Nevertheless, the souls still yearn to unravel the truth of the case and accept the Grim Reaper’s terms.

This time, the one who has arrived at this Grim Reaper Detective Agency is…