\documentclass[a4j]{utarticle}
\usepackage{kanruby}
\def\yen{\noautoxspacing\symbol{92}}%
\begin{document}
\noindent
いろいろなサイズの漢文を書いた例です。
\bigskip

\kanrubyon
\let\kanrubysize=\tiny
\noindent
% \smallより\kansmallの方が訓点等の位置がうまく調整される。
{\kansmall
\Kan{見}{}{}{二}
\Kan{胤}{いん}{ヲ}{}
於童幼之
\Kan{中}{うち}{ニ}{一}
\Kuto{、}
\Kan{謂}{}{ヒテ}{二}
\Kan{胤}{}{ノ}{}
\Kan{父}{}{ニ}{一}
\Kan{曰}{}{ク}{}
\Kuto{、}\Kagibegin
\Kan{此}{}{ノ}{}
児
\Kan{当}{}{ニ}{三}\Sai{べ}{シ}
\Kan{大}{}{イニ}{}
\Kan{興}{}{ス}{二}
\Kan{卿}{}{ノ}{}
\kanchusenx
\Kan{門}{}{ヲ}{一}
\Kuto{、}
\Kan{可}{}{シト}{\kanre}
\Kan{使}{}{ム}{二}
\Kan{専}{}{}{}
\kanchusenx
\Kan{学}{}{セ}{一}
\Kuto{。}\Kagiend}\ ({\tt \yen{}small})

\let\kanrubysize=\tiny
\noindent
{\kannormalsize
\Kan{見}{}{}{二}
\Kan{胤}{いん}{ヲ}{}
於童幼之
\Kan{中}{うち}{ニ}{一}
\Kuto{、}
\Kan{謂}{}{ヒテ}{二}
\Kan{胤}{}{ノ}{}
\Kan{父}{}{ニ}{一}
\Kan{曰}{}{ク}{}
\Kuto{、}\Kagibegin
\Kan{此}{}{ノ}{}
児
\Kan{当}{}{ニ}{三}\Sai{べ}{シ}
\Kan{大}{}{イニ}{}
\Kan{興}{}{ス}{二}
\Kan{卿}{}{ノ}{}
\kanchusenx
\Kan{門}{}{ヲ}{一}
\Kuto{、}
\Kan{可}{}{シト}{\kanre}
\Kan{使}{}{ム}{二}
\Kan{専}{}{}{}
\kanchusenx
\Kan{学}{}{セ}{一}
\Kuto{。}\Kagiend}\ ({\tt \yen{}normalsize})

\noindent
{\kanlarge
\Kan{見}{}{}{二}
\Kan{胤}{いん}{ヲ}{}
於童幼之
\Kan{中}{うち}{ニ}{一}
\Kuto{、}
\Kan{謂}{}{ヒテ}{二}
\Kan{胤}{}{ノ}{}
\Kan{父}{}{ニ}{一}
\Kan{曰}{}{ク}{}
\Kuto{、}\Kagibegin
\Kan{此}{}{ノ}{}
児
\Kan{当}{}{ニ}{三}\Sai{べ}{シ}
\Kan{大}{}{イニ}{}
\Kan{興}{}{ス}{二}
\Kan{卿}{}{ノ}{}
\kanchusenx
\Kan{門}{}{ヲ}{一}
\Kuto{、}
\Kan{可}{}{シト}{\kanre}
\Kan{使}{}{ム}{二}
\Kan{専}{}{}{}
\kanchusenx
\Kan{学}{}{セ}{一}
\Kuto{。}\Kagiend}\ ({\tt \yen{}large})

\let\kanrubysize=\scriptsize
\noindent
{\kanLarge
\Kan{見}{}{}{二}
\Kan{胤}{いん}{ヲ}{}
於童幼之
\Kan{中}{うち}{ニ}{一}
\Kuto{、}
\Kan{謂}{}{ヒテ}{二}
\Kan{胤}{}{ノ}{}
\Kan{父}{}{ニ}{一}
\Kan{曰}{}{ク}{}
\Kuto{、}\Kagibegin
\Kan{此}{}{ノ}{}
児
\Kan{当}{}{ニ}{三}\Sai{べ}{シ}
\Kan{大}{}{イニ}{}
\Kan{興}{}{ス}{二}
\Kan{卿}{}{ノ}{}
\kanchusenx
\Kan{門}{}{ヲ}{一}
\Kuto{、}
\Kan{可}{}{シト}{\kanre}
\Kan{使}{}{ム}{二}
\Kan{専}{}{}{}
\kanchusenx
\Kan{学}{}{セ}{一}
\Kuto{。}\Kagiend}\ ({\tt \yen{}Large})

\noindent
{\kanLARGE
\Kan{見}{}{}{二}
\Kan{胤}{いん}{ヲ}{}
於童幼之
\Kan{中}{うち}{ニ}{一}
\Kuto{、}
\Kan{謂}{}{ヒテ}{二}
\Kan{胤}{}{ノ}{}
\Kan{父}{}{ニ}{一}
\Kan{曰}{}{ク}{}
\Kuto{、}\Kagibegin
\Kan{此}{}{ノ}{}
児
\Kan{当}{}{ニ}{三}\Sai{べ}{シ}
\Kan{大}{}{イニ}{}
\Kan{興}{}{ス}{二}
\Kan{卿}{}{ノ}{}
\kanchusenx
\Kan{門}{}{ヲ}{一}
\Kuto{、}
\Kan{可}{}{シト}{\kanre}
\Kan{使}{}{ム}{二}
\Kan{専}{}{}{}
\kanchusenx
\Kan{学}{}{セ}{一}
\Kuto{。}\Kagiend}\ ({\tt \yen{}LARGE})

\noindent
\let\kanrubysize=\footnotesize
{\kanhuge
\Kan{見}{}{}{二}
\Kan{胤}{いん}{ヲ}{}
於童幼之
\Kan{中}{うち}{ニ}{一}
\Kuto{、}
\Kan{謂}{}{ヒテ}{二}
\Kan{胤}{}{ノ}{}
\Kan{父}{}{ニ}{一}
\Kan{曰}{}{ク}{}
\Kuto{、}\Kagibegin
\Kan{此}{}{ノ}{}
児
\Kan{当}{}{ニ}{三}\Sai{べ}{シ}
\Kan{大}{}{イニ}{}
\Kan{興}{}{ス}{二}
\Kan{卿}{}{ノ}{}
\kanchusenx
\Kan{門}{}{ヲ}{一}
\Kuto{、}
\Kan{可}{}{シト}{\kanre}
\Kan{使}{}{ム}{二}
\Kan{専}{}{}{}
\kanchusenx
\hspace{0.02zw}
\Kan{学}{}{セ}{一}
\Kuto{。}\Kagiend}\ ({\tt \yen{}huge})

\noindent
{\kanHuge
\Kan{見}{}{}{二}
\Kan{胤}{いん}{ヲ}{}
於童幼之
\Kan{中}{うち}{ニ}{一}
\Kuto{、}
\Kan{謂}{}{ヒテ}{二}
\Kan{胤}{}{ノ}{}
\Kan{父}{}{ニ}{一}
\Kan{曰}{}{ク}{}
\Kuto{、}\Kagibegin
\Kan{此}{}{ノ}{}
児
\Kan{当}{}{ニ}{三}\Sai{べ}{シ}
\Kan{大}{}{イニ}{}
\Kan{興}{}{ス}{二}
\Kan{卿}{}{ノ}{}
\kanchusenx
\Kan{門}{}{ヲ}{一}
\Kuto{、}
\Kan{可}{}{シト}{\kanre}
\Kan{使}{}{ム}{二}
\Kan{専}{}{}{}
\kanchusenx
\hspace{0.02zw}
\Kan{学}{}{セ}{一}
\Kuto{。}\Kagiend}\ ({\tt \yen{}Huge})

\kanrubyoff
\end{document}