This module is called by Template:Shogi diagram.
As the original template used .pngs/.svgs, when many templates were used on pages, the page load times became a bit long. In order to fix this, this module instead uses text. And, text is preferable anyway since it renders very sharp edges. The drawback is that it depends on web browser for rotated text – that is, the web browser must be a modern one.
It was based on Module:Chessboard.