Font designers have to literally author each letter and there are thousands of them...
Fortunately, there are enough interests in Japanese fonts, so there are varieties of them. The problem is that many of them are fairly expensive to license perhaps because of work involved making them. (Thus, most of people use ones come with the OS; in case of OS X, they bundle premium fonts. Japanese government also distributes free fonts,[0]) I don't know the situation for Chinese, but probably similar situation.
Font designers have to literally author each letter and there are thousands of them...
Fortunately, there are enough interests in Japanese fonts, so there are varieties of them. The problem is that many of them are fairly expensive to license perhaps because of work involved making them. (Thus, most of people use ones come with the OS; in case of OS X, they bundle premium fonts. Japanese government also distributes free fonts,[0]) I don't know the situation for Chinese, but probably similar situation.
[0]: http://ipafont.ipa.go.jp/