For example, first place I checked: http://yahoo.co.jp doesn't have any subtle brush-strokes. Everthing chracter is constant thickness. The characters are intricate, but I don't know what the information density is (pixels per word); I think they have fewer charaters per idea in Japanese, and more essential pixels per character.
Interestingly, that appears to not be the case for Japanese, quite the opposite in fact. There was a research a while ago about the speed of spoken language that I think can loosely be applied here (number of characters per syllable depends on which Japanese alphabet is being used). The research concluded that Japanese is very low density (and thus spoken very fast).
The Japanese syllabary characters tend to be quite modestly formed; they have few essential pixels per character. The kanji, which carry large quantities of semantic information, require much more space to be legible.