From Atsushi Toyokura in pkgsrc-wip
The set of the Japanese logical fonts (JFMs) that are used as
standard fonts in pTeX and upTeX contains both Unicode JFMs and
non-Unicode JFMs. This bundle provides an alternative set of
non-Unicode JFMs that are tied to the virtual fonts (VFs) that
refer to the glyphs in the Unicode JFMs. Moreover it provides a
LaTeX package that redefines the NFSS settings of the Japanese
fonts of (u)pLaTeX so that the new set of non-Unicode JFMs will
be employed. As a whole, this bundle allows users to dispense
with the mapping setup on non-Unicode JFMs. Such a setup is
useful in particular when users want to use OpenType fonts
(such as Source Han Serif) that have a glyph encoding different
from Adobe-Japan1, because mapping setups from non-Unicode JFMs
to such physical fonts are difficult to prepare.
