Thunderbird and chinese fonts

I've been having this problem for a while, but I never bothered to
really look into it, but now, I want to do something about it.

Thing is, when I view messages in Thunderbird - I use TB13 - that are
encoded in GB2312 and have chinese characters in them, the font looks
rather ugly. Unicode messages with or without chinese characters look
much better. I attached a screenshot for you to see what I mean.

I googled around for a bit but all the guides I could find were really
outdated or pointed to other guids that were also outdated.

So I tried installing some of the suggested fonts, bit that did nod
solve the problem.

$ qlist -I | grep media-fonts
media-fonts/arphicfonts
media-fonts/bitstream-cyberbit
media-fonts/cantarell
media-fonts/corefonts
media-fonts/dejavu
media-fonts/droid
media-fonts/encodings
media-fonts/font-alias
media-fonts/font-bh-ttf
media-fonts/font-bh-type1
media-fonts/font-daewoo-misc
media-fonts/font-isas-misc
media-fonts/font-misc-misc
media-fonts/font-util
media-fonts/liberation-fonts
media-fonts/libertine-ttf
media-fonts/terminus-font
media-fonts/ttf-bitstream-vera
media-fonts/unifont
media-fonts/urw-fonts

Fonts under linux are still a little bit of a mystery to me to be
honest. So I hope one of you guys could help me out.

Oh, I use GNOME3 (3.4.x from the overlay) if it's relevant. And yes,
except for some small details, I like my GNOME3:)