I recently opened a GitHub issue requesting Japanese (ja) language support in the Crowdin translation project:
To support this effort, I have already started building and publishing Japanese localization resources here:
The project currently includes:
.po translation files
Translation utilities
Japanese terminology alignment work
Localization workflow experiments for Frappe environments
My intention is to contribute long-term Japanese localization support not only for Frappe Framework, but also ERPNext and related apps.
If anyone from the community is interested in Japanese localization or has advice regarding the existing translation workflow, I would appreciate your feedback.