As a temperary solution go to blindaudiogames.com
Ian reed has written the jgt addon which works for japanese games, you will need a username and password on his site as he is paying for the translations for these games and the translations are cached on his server.
He eventually hopes to have all the translated japanese games at least on his server making as little requests to google as he can.
Its not an official nvda addon but it works, another unofficial addon which is on the jeff.tdrealms.com nvda site with all the others is if interpriters by nick stockman or is it stockton.
This handles glulx and a few other interpriters this one is not official and has not had updates for a while but its good.
The only thing one needs to do with winfrotz is to start the program first before opening a game with glulx this is fine.
Sadly google translate will not work by addon but you should still be able to translate webpages, there is a user limit on it to.