So, I purchased the Princess Maker Memorial Box which contains all 5 games, in Japanese. Of those five, one of them can be hex-edited into English if you are bloody-minded enough, one of them had an English beta that can be found online, and the last two are accessible through a 'hook' program that extracts the japanese text, allowing you to run it through babelfish or other translation tools you might have. None of this is easy, but they can all be done.
If you're counting, you realise that leaves one more. Princess Maker 3, the one in the middle, is encrypted so that it can't be directly edited and uses an engine that doesn't play nicely with hook programs. There is, as far as I can tell, no way to make any sense out of it.
Playing through (just once so far) was enough to get me to start picking up some katakana, but... I suspect this game may not get much play out of me. There's too many long conversations between characters where I have no idea what's happening, or times where I'm asked to make a decision and don't know what my options are. The sim part of it is easily faked - you can see stats going up and down even if you can't always remember exactly what they are. Conversations are a bigger problem.