css/css-fonts/system-ui-ja.html

<!doctype html>
<html lang="ja">
<title>Tests that system-ui font-family works for Japanese</title>
<link rel="help" href="https://drafts.csswg.org/css-fonts/#system-ui-def">
<link rel="help" href="https://www.unicode.org/faq/han_cjk.html#3">
<link rel="author" title="Jonathan Kew" href="mailto:jkew@mozilla.com">
<link rel="mismatch" href="system-ui-ja-notref.html">
<link rel="stylesheet" href="/fonts/ahem.css">
<style>
@font-face {
  font-family: mplus;
  src: url(/fonts/mplus-1p-regular.woff);
  size-adjust: 50%; /* cause mismatch even if system-ui maps to M+ */
}
p {
  font-family: Ahem, system-ui, mplus, serif;
  font-size: 4em;
}
</style>
<p>&#x76F4;</p>  <!-- U+76F4 has distinct Japanese vs Chinese shapes, see Unicode FAQ -->