documentclass{article}

usepackage[T1]{fontenc}
usepackage{CJKutf8}
usepackage[record,style=indexgroup,nomain]{glossaries-extra}

newglossary*{japanese}{Japanese to English}
newglossary*{english}{English to Japanese}

newrobustcmd{cjkname}[1]{begin{CJK}{UTF8}{ipxm}#1end{CJK}}
glsnoexpandfields

newcommand*{englishlettergroup}[1]{#1}
newcommand*{japaneselettergroup}[1]{cjkname{#1}}
newcommand*{bibglslettergrouptitle}[4]{unexpanded{csuse{#4lettergroup}{#1}}}

GlsXtrLoadResources[
  src=testcjk2,% bib file
  sort={ja-JP},% locale used to sort primary entries
  dual-sort={en-GB},% locale used to sort secondary entries
  type=japanese,% put the primary entries in the 'japanese' glossary
  dual-type=english% put the dual entries in the 'english' glossary
]

begin{document}

begin{CJK}{UTF8}{ipxm}日本語はだいじょうぶend{CJK}

Japanese: gls{squareroot}

English: gls{dual.squareroot}

printunsrtglossaries
end{document}

@dualentry{squareroot,
  name={cjkname{ルート}},
  description={square root}
}