Perhaps something like this:

To do this I have used tikz to define a command \Genkoyoashi that accepts optional arguments to change the appearance. The images above were generated by:
\Genkoyoshi
\Genkoyoshi[color=red, columns=10, size=1.2, rows=10]
In general, the optional arguments are key-value pairs to set:
color: the colour of the template (default: MidnightBlue - requires svgnames)
columns: the number of columns (default: 20)
rows: the number of rows (default: 20)
size: sets the size/scale of the boxes (default: 0.7)
Here is the full code:
\documentclass[svgnames]{article}
\usepackage{tikz}
\parindent0pt
\tikzset{
/genkoyoshi/.cd,
color/.initial=MidnightBlue,
columns/.initial=20,
rows/.initial=20,
size/.initial=0.7
}
\newcommand\GeNkOyOsHi[1]{\pgfkeysvalueof{/genkoyoshi/#1}}
\newcommand\Genkoyoshi[1][]{%
\begin{center}
\tikzset{/genkoyoshi/.cd, #1}
\begin{tikzpicture}[scale=\GeNkOyOsHi{size}]
\foreach \lin in {1,...,\GeNkOyOsHi{rows}} {
\draw[\GeNkOyOsHi{color}] (0,-\lin)--++(0.7*\GeNkOyOsHi{columns},0);
\draw[\GeNkOyOsHi{color}] (0,-\lin-0.7)--++(0.7*\GeNkOyOsHi{columns},0);
\foreach \bx in {0,...,\GeNkOyOsHi{columns}} {
\draw[\GeNkOyOsHi{color}] (\bx*0.7, -\lin)--++(0,-0.7);
}
}
\draw[\GeNkOyOsHi{color},thick] ([yshift=3mm]current bounding box.north west)
rectangle ([yshift=-3mm]current bounding box.south east);
\end{tikzpicture}
\end{center}
}
\begin{document}
\Genkoyoshi
\Genkoyoshi[color=red, columns=10, size=1.2, rows=10]
\end{document}