Just to point out, to be a Japanese interpreter, you're looking at something at a minimum six years down the road unless you can move to Japan for at least two years after studying two years prior to going.
And that's assuming you are very good at learning languages (which it seems you are). Polyglottery is awesome.
But it is (almost) cheating to count Swedish, Danish, and Norwegian as three languages! It's not fair. The best I can do with my native language is a very tiny bit of German and Dutch, but that is a very, very little bit. Well, I can read a bit of Scots...
Fortunately I learned Spanish at an early age, so I can read some French, Italian, and Portuguese.
But good luck, noneedforname!