Tokyo is host to many of Japan's largest companies and is the centre of its economy, meaning it's an attractive place to move, especially for young people living in rural areas. This migration pattern has left small towns with fewer and older residents, and millions of unoccupied homes.

Tokyo’s overcrowding in 2026 is less about total land area and more about population density and the concentration of economic activity. Greater Tokyo is the most populous metropolitan area in the world, housing over 37 million people. This leads to "human congestion" in key nodes, particularly during the morning and evening rush hours where train stations like Shinjuku handle over 3.5 million passengers daily. High density has driven a "Compact City" policy, leading to vertical living in high-rise towers to maximize limited ground space. While Tokyo is famously efficient, the overcrowding manifests in long average commute times (often 60–90 minutes), tiny "micro-apartments" (often under 20sqm), and a lack of green space per capita. Despite a shrinking national population, Tokyo continues to attract internal migrants and global talent, keeping the "pressure" on its infrastructure and housing market at record-high levels.