Aegisub/packages/osx_bundle/Contents/Resources/etc/fonts/conf.d/20-fix-globaladvance.conf

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
<!--
  Some Asian fonts misadvertise themselves as monospaced when
  in fact they are dual-spaced (half and full).  This makes
  FreeType very confused as it forces all widths to match.
  Undo this magic by disabling the width forcing code -->
	<match target="font">
		<test name="family"><string>GulimChe</string></test>
		<edit name="globaladvance"><bool>false</bool></edit>
	</match>

	<match target="font">
		<test name="family"><string>DotumChe</string></test>
		<edit name="globaladvance"><bool>false</bool></edit>
	</match>

	<match target="font">
		<test name="family"><string>BatangChe</string></test>
		<edit name="globaladvance"><bool>false</bool></edit>
	</match>

	<match target="font">
		<test name="family"><string>GungsuhChe</string></test>
		<edit name="globaladvance"><bool>false</bool></edit>
	</match>
</fontconfig>