For the first time in recorded human history, a single nation counts more than 100,000 citizens who have reached the age of 100 — and that nation is Japan. This milestone, confirmed in 2026, is not the product of chance but of deliberate arrangement: decades of accessible healthcare, nutritional stability, and social cohesion that have made extreme old age a demographic pattern rather than a personal exception. Yet every triumph carries its own weight, and Japan now stands at the frontier of a question no society has yet fully answered — how does a civilization sustain itself when longevity ou