The Current estimate of Japan's population is 127,704,000 people. It is rather crowded in Japan, but that doesn't say anything bad about it. From the looks of it, the peak of Japan's population will be in 2011. From there it looks like it starts to decrease.
Here are some other facts about Japan.
Geographic coordinates: 36 00 N, 138 00 E
Area: total: 377,915 sq km land: 364,485 sq km water: 13,430 sq km
Religions: Shintoism 83.9%, Buddhism 71.4%, Christianity 2%, other 7.8%
Races: Japanese 98.5%, Koreans 0.5%, Chinese 0.4%, other 0.6%