Narrow fonts for Chinese characters?
I believe the option to choose "half-width" or 半角, as opposed to "full-width" 全角, is used in Chinese input systems only for punctuation and other symbols, but not for Chinese characters.

You can read more about it here:

http://blog.csdn.net/kevinhg/article/details/8702462

From what I can discern, the original reason for having "narrow-width" and "full-width" characters was to make sure that CJK and English text could be properly aligned.