In a nameless, secluded village, the boy Hotaru and the girl Arista live together in quiet harmony. Their peaceful existence is shattered when Arista is suddenly taken away, and that forced separation becomes the catalyst that thrusts Hotaru into a world he never knew existed. He learns that the reality he inhabited was a lie, and the truth concealed beneath the surface is far darker and more monstrous than he could have imagined.

The setting expands from the remote village into a landscape where giant creatures roam and a hidden society operates in the shadows. Hotaru is captured alongside a companion named Kuro and faces a public execution, an ordeal that peels back the first layers of the world's corruption. To survive and fight back, Hotaru begins training to master a specialized technique called the Higan Dan, a power that allows him to confront the monstrous threats directly. This training leads him to a rematch with an enemy named Migidari.

After the brutal conclusion of a battle with a foe called Shappman, Hotaru journeys to the Sixth District, a new and dangerous region where he encounters a mysterious and enigmatic man named Fox. This meeting pushes the story into its next phase, guiding Hotaru toward the final confrontation. In the ultimate volume, Hotaru faces the decisive battle that resolves the central conflict, and the great secret hidden at the core of this world is finally laid bare. The narrative unfolds as a dark, fast-paced action story centered on monsters, hidden truths, and a boy forced to grow up in a world that is not what it seemed.