There is a known problem - Issue 7160: Wrong font for Japanese characters in English language Chrome, dating from January 2008 but unfixed until today.
Only workarounds contributed by users are available, none of which is perfect and some contradict each other.
It seems that the only real solution at the moment is to keep on using Firefox.
Workaround 1 : Issue 7160: Wrong font for Japanese characters in English language Chrome
In the font and language settings, set
Serif Font to MS PMincho; Sans-Serif
Font to Meiryo; Fixed-Width Font to MS
This yields the correct glyphs for all
Japanese sites. English looks as usual
in Sans-Serif (most of the Web), but
a bit harder to read in Fixed-Width
Workaround 2 : Chromium and font
Since I'm in Japan (but I would rather
use English), google defaults to the
japanese site. On this, all the text
becomes squares. However, I installed
Droid font from AUR. It comes
with Japanese font, and that fixed it.
Now when I go to google, I can
actually read the Japanese webpage
Workaround 3 : How to display Japanese characters in Google Chrome/Chromium?
remove google-droid fonts:
yum remove google-droid*