The aging of Japan's workforce is accelerating at a striking pace. Back in 1965, the average age was just 29 years—characteristic of a younger, growing population. By 1995, this had climbed to 38 years as birth rates declined. Fast forward to 2025, and Japan's median age now sits at 48 years, marking one of the world's most aged societies. This demographic shift carries major implications: shrinking labor pools, rising healthcare costs, and structural pressures on fiscal policy. For markets and investors tracking macroeconomic cycles, Japan's aging trajectory offers a preview of what developed economies will face—and how central banks may respond with prolonged low-rate environments.