You should be able to decrypt the file with the RPG Maker decryption tool and then move the images over. Though they would probably need to be renamed? Seems really difficult
With the caveat that I've never tried this, I think you can do it without decrypting.
If you look in the subfolders of www\img\karryn, you see that all the files have a version that ends in _cen and one that doesn't. When you play the English version, it uses the uncensored and when you play Japanese, it uses censored.
You should be able to rename or remove all the _cen files and then rename all the non-cen files to have _cen at the end. That should trick the Japanese language game into using the non censored images. If you know any scripting languages, like PowerShell, this shouldn't be too hard, or look for bulk-renaming utilities at C-net or someplace like that.