Known in the US (and possibly other countries) as "anime", Japanese animation is a highly stylized form of animation that has slowly increased in global popularity over the past several decades. It's unusual for several reasons, among them: (1) characters are drawn with large, expressive eyes; (2) a lot of anime is aimed at teenagers and young adults; (3) there is a strong emphasis on real character development and non-trivial stories.
A few interesting anime series:
An ancient artform which reached its absolute pinnacle several years ago with the creation of Neon Genesis Evangelion
http://en.wikipedia.org/wiki/Neon_Genesis_Evangelion
The same could be said to be true for "reality". -- EmlynShannon
(3) there is a strong emphasis on real character development and non-trivial stories.
This is true for some Japanese animation, and probably more true than for US animation, but hardly universal.
See ParodyMode?
Japanese animation is known as "anime" outside Japan, but in Japan "anime" means any animation, regardless of origin.
Anime fans should be aware that anime fandom isn't more mainstream in Japan; it's simply a larger economic force. There's more anime to watch, more anime merchandise to buy, more anime events to attend, and more anime geeks, known as 'otaku', with which to commune. But outside this clique, obsessive fandoms carry just as big a stigma as the ComicBookGuy? in the United States -- possibly worse, in such a conformist society.