Summoned as a Hero, Kazuki is branded "defective" with F-rank magic. Yet, a god's error granted him the Elder Codex—authority over reality's True Names. Isolated and scorned, he hides overwhelming power while his classmates bask in glory. But when ancient shadows rise, his silent commands unravel monsters and magic alike, revealing the unseen sovereign. As war looms, a princess, an elf, and other extraordinary women are drawn to the gentle boy with a god's power, forging a destined harem to challenge the Demon King. The true hero was hiding in plain sight all along.