adamrice / #pdf

https://compacto.app/

Compress, merge, split, protect and convert PDFs on your Mac — entirely offline. Compacto is free to use with no accounts, no uploads, no subscriptions. Buy Pro tools once, own them forever.

http://wkhtmltopdf.org/docs.html

command-line tool converts HTML to PDF

http://weasyprint.org/

http://convertpdftoword.net/

Does what it says on the tin. Apparently can handle Japanese.