/usr/lib/dvi2ps/fontsk/mul-bikanji is in dvi2ps 5.1j-1.2build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | # built-in kanji
# jfm MuLTeX with dm* dg*
font jfm * 0 $tmf/tfm/muling/ntttwo/
map dm%d JSMR Ryumin-Light-H
map dg%d JSMR GothicBBB-Medium-H
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