\documentclass{ltjsarticle}
\usepackage{luatexja-fontspec,luatexja-adjust,xcolor,amsmath,amssymb}
+\DeclareKanjiFamily{JY3}{piyo}{}
+\DeclareFontShape{JY3}{piyo}{m}{n}{<-> s*[\Cjascale] file:ipaexg.ttf:jfm=jlreq}{}
\def\sq{%
\hbox to 1\zw{\hss\fboxsep=-.5\fboxrule\fbox{%
+\newpage
+
+\def\MYGUARDA#1{ \kern-\zw#1\kern-\zw \ignorespaces}
+\def\MYGUARDB#1{{\kanjifamily{mc}\selectfont }%
+ \kern-\zw#1\kern-\zw{\kanjifamily{mc}\selectfont }\ignorespaces}
+\def\MYGUARDC#1{\ltjghostjachar#1\ltjghostjachar\ignorespaces}
+\def\MYVRULE{\raisebox{-2pt}{漢}}
+
+\paragraph{jfm: ujis}\
+
+\leavevmode\hbox to 15\zw{◆\MYVRULE ◆◆◆◆$f$◆}\par
+\leavevmode\hbox to 15\zw{◆\MYGUARDA{\MYVRULE}◆◆◆◆$f$◆} A\par
+\leavevmode\hbox to 15\zw{◆\MYGUARDB{\MYVRULE}◆◆◆◆$f$◆} B\par
+\leavevmode\hbox to 15\zw{◆\MYGUARDC{\MYVRULE}◆◆◆◆$f$◆} C\par
+\leavevmode\hbox to 15\zw{◆◇◆◆◆◆$f$◆} 比較用\par
+
+\paragraph{jfm: jlreq}\
+\kanjifamily{piyo}\selectfont
+\leavevmode\hbox to 15\zw{◆\MYVRULE ◆◆◆◆$f$◆}\par
+\leavevmode\hbox to 15\zw{◆\MYGUARDA{\MYVRULE}◆◆◆◆$f$◆} A\par
+\leavevmode\hbox to 15\zw{◆\MYGUARDB{\MYVRULE}◆◆◆◆$f$◆} B\par
+\leavevmode\hbox to 15\zw{◆\MYGUARDC{\MYVRULE}◆◆◆◆$f$◆} C\par
+\leavevmode\hbox to 15\zw{◆◇◆◆◆◆$f$◆} 比較用\par
\end{document}