As of the last census in October, Tokyo is home to 10% of the nation's population. 91,000 more people came to live in Tokyo during 2007. So if the trains seem more crowded, that's why.
This is the highest percentage it's been since 1979. The highest ever was 11.1% in the late 1960s.
Japan's shifting population is interesting. 37 rural prefectures lost population last year. People over 75 outnumber people under 14 in a half dozen prefectures. Deaths outnumbered births by 2,000 nationwide. What will the next census tell us?
Stupid 91,000 more people ... grumble, grumble