fontconfig.xml

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
  <alias>
    <family>Noto Sans</family>
    <default><family>sans-serif</family></default>
  </alias>

  <alias>
    <family>Noto Sans JP</family>
    <default><family>sans-serif</family></default>
  </alias>

  <alias>
    <family>Rakuten Sans</family>
    <prefer>
			<family>Noto Sans JP</family>
    </prefer>
    <default>
      <family>sans-serif</family>
    </default>
  </alias>

  <alias>
    <family>Fira Code</family>
    <prefer>
			<family>Noto Sans JP</family>
    </prefer>
    <default>
      <family>monospace</family>
    </default>
  </alias>

	<alias binding="strong">
		<family>monospace</family>
		<prefer>
			<family>Fira Code</family>
		</prefer>
	</alias>

	<alias binding="strong">
		<family>sans-serif</family>
		<prefer>
			<family>Noto Sans</family>
			<family>Noto Sans JP</family>
		</prefer>
	</alias>
</fontconfig>