Since your output still seems to be some flavor of SGML/XML but modified from the original I think what you might really be after is XSLT instead of XML handling. This may be something a bit out of reach for a beginner unless you have strong technical aptitude or programming experience. :( Sidenote: you should probably fire your Japanese translator. Seems she's been hitting the Campari a little hard.

The packages I think you want are XML::LibXML and XML::LibXSLT. If you break it into small pieces and show what you've tried, you'll be able to get a ton of help here. There is also https://jobs.perl.com if you just want to hire someone to write the code for you.