fonts.xml

<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
<fontconfig>

<!-- Default font (no fc-match pattern) -->
 <match>
  <edit mode="prepend" name="family">
   <string>Source Han Sans</string>
  </edit>
 </match>

<!-- Default font for the ja_JP locale (no fc-match pattern) -->
 <match>
  <test compare="contains" name="lang">
   <string>ja</string>
  </test>
  <edit mode="prepend" name="family">
   <string>Source Han Sans JP</string>
  </edit>
 </match>

<!-- Default sans-serif font -->
 <match target="pattern">
   <test qual="any" name="family"><string>sans-serif</string></test>
   <!--<test qual="any" name="lang"><string>ja</string></test>-->
   <edit name="family" mode="prepend" binding="same"><string>Source Han Sans JP</string>  </edit>
 </match>
 
<!-- Default serif fonts -->
 <match target="pattern">
   <test qual="any" name="family"><string>serif</string></test>
   <edit name="family" mode="prepend" binding="same"><string>Source Han Serif JP</string>  </edit>
 </match>

<!-- Default monospace fonts -->
 <match target="pattern">
   <test qual="any" name="family"><string>monospace</string></test>
   <edit name="family" mode="prepend" binding="same"><string>Inconsolata LGC</string></edit>
   <edit name="family" mode="append" binding="same"><string>Liberation Mono</string></edit>
   <edit name="family" mode="append" binding="same"><string>Source Han Sans JP</string>  </edit>
 </match>

<!-- Fallback fonts preference order -->
 <alias>
  <family>sans-serif</family>
  <prefer>
   <family>Source Han Sans JP</family>
   <family>Liberation Sans</family>
  </prefer>
 </alias>
 <alias>
  <family>serif</family>
  <prefer>
   <family>Source Han Serif JP</family>
   <family>Liberation Serif</family>
  </prefer>
 </alias>
 <alias>
  <family>monospace</family>
  <prefer>
    <family>Inconsolata LGC</family>
    <family>Liberation Mono</family>
    <family>Source Han Sans JP</family>
  </prefer>
 </alias>

 <!--dir>~/.fonts</dir-->
</fontconfig>