Is Google Translate totally useless? I've found it does a great job of providing audio in and out, as well as romanization so you can do a hack job from zero. Google Translate even seems to offer a limited IME so you can type roman or kana and it'll guess the kanji.

Shopping in Korean, I can just set it to OCR mode and sorta read labels I don't understand. (Of course, Hangul's probably a lot easier to OCR than kana+kanji.) I've also found that while the store people will respond to me in Korean if they don't see me, once they realize it's me they flip into a common third tongue.

I've even had "conversations" in other languages just by pressing the flip button and letting the other person talk. They can correct any audio recognition failures or just type.

In general, the translations for simple stuff and interactions seem pretty good. Sometimes you need the alternative translations to find one that is accurate. But I wouldn't say you "cannot speak, listen, write, or read anything".

OTOH, sometimes it has odd things. Formal-something I (吾輩) like from the "I am a cat" gets translated as "Spence" (I think the pronoun isn't used much). Or maybe one possible pronunciation of them is close enough to Spence it's used as a name in some place that uses those characters?

Not to mention, you can pick up the kana in a week, and at least the meanings of the basic kanji in a month or two, claims the guy that made the book that did teach me kana in a week. I'd assume if you're gonna go to Japan and be serious, you'd at least listen to the first 10 Pimsleur sessions for basic "hi I can't speak Japanese", and learn the scripts somewhat.