Gentle ways to learn Japanese?

I am starting my career in the Marines and plan on being stationed in Japan. I'm a Native English speaker and also hold a modest mastery over French, however I'm concerned how I'll be able to adapt to learning a truly foreign language with no latin roots I can draw back to. I'm in a debate whether or not to just wait and go there then simply hire a Native tutor which I think would be beneficial, or try to tackle this language like I did French. Could someone with experience with the language give me some advice about the best methods, someone who's mother tongue is Japanese would be Godsend.