Use IPA fonts in your PDF:

ipam.ttf
ipag.ttf

Usage:

dvipdfmx -f ./texfonts.map abstract.dvi

texfonts.map:

rml  H :0:ipam.ttf
gbm  H :0:ipag.ttf
rmlv V :0:ipam.ttf
gbmv V :0:ipag.ttf