I don't what?

It's a bad example sentence.
I'd suggest not translating it.

Go to this one.

[#437021] I want a room for tonight. (lukaszpp) *audio*

@CK
Are yoг sure, the German sentence is bad, too? You don't speak any German. It seems we need somebody, who speaks it to ask.

It is not so much a question of knowing German, but of whether these sentences are of any use ( ,even if they are fully correct).
'No, I don't.' can only be meaningful (and translateable) when we know the question.
Here, the answer in German is something like "No, I don't want" (it or to), which seems to be narrower than in English.

@ brauchinet
My knoledge of German is very poor (only few simple words and phrases). I understand this sentence as a rejection of some proposal: "No, I don't want. I would like (what is Raum?) for this night."
I don't know, what is "Raum", but in general it seems meangful.
Also Vortarulo is a native German speaker, so I think it should be correct.

So, my suggestion is stay the German sentence as is if it's good by yourself and align the English one with it. I can't say anything about the Japanese. It's unowned, most likely should be changed or deleted.