Shinonome Oden, who became a death-row inmate due to a certain crime, is sentenced to "Excavation Duty"—a penalty where her execution is postponed in exchange for mining the rare and dangerous ore "Bogosort." Together with her partner in crime, Slumber, she is taken to Gray-mole, the mysterious massive ruin that is the source of Bogosort. In this demon's den filled with outlaws and dangerous creatures, Oden's life-or-death mineral mining days begin――! A pop and thrilling prison comedy that depicts the chaotic joy and sorrow of the prisoners, begins now!