JP_KANTO
World's richest metro at $2.55T GDP; 37M people generate 30% of Japan's output across Tokyo, Yokohama, and the Keihin industrial corridor.
Kantō is where Japan concentrates. The Greater Tokyo Area—spanning Tokyo Metropolis plus Chiba, Gunma, Ibaraki, Kanagawa, Saitama, Tochigi, and Yamanashi prefectures—houses 37 million people on 13,000 square kilometers. That's nearly 30% of Japan's population generating the world's richest metropolitan GDP: $2.55 trillion in 2025, surpassing New York to claim the top spot.
The economic density defies imagination. Tokyo hosts 29 Fortune Global 500 headquarters—second only to Beijing. Mitsubishi UFJ, Sony, Honda, and Toyota maintain major operations here. Finance, technology, manufacturing, and services intermesh in ways that resist separation. The Keihin industrial region (Tokyo-Yokohama corridor) produces everything from automobiles to electronics to pharmaceuticals.
Population concentration creates corresponding challenges. Housing costs constrain workforce growth. Aging demographics pressure pension and healthcare systems. Earthquake risk means that the world's largest economy operates atop active fault lines—a vulnerability that no diversification strategy fully addresses.
By 2026, Kantō will likely remain Japan's overwhelming economic center even as population gradually disperses to regional cities. Oxford Economics projects Tokyo will remain the world's largest metropolitan economy until approximately 2034, when Shanghai may overtake. Until then, and likely beyond, Kantō defines what Japan is: concentrated, productive, irreplaceable.