The package WILL provide a framework to use the biblatex package for making bibliographies in Japanese articles and books. The development of the package has been just started; the package is not practical at present.
The present version is designed to work with at least v3.4 of biblatex.
The details are explained in doc/biblatex-japanese.pdf (now only available in Japanese).
The package may be distributed and/or modified under the terms of the 2-clause BSD license (see LICENSE).
Issues and pull requests via Github are welcome.