Learning Japanese is fun. Here's what you do. Start by taking real actual classes, because they'll teach you how sentence structure works, how to do formal/casual forms of speech, what the heck is up with articles, etc. Important groundwork type stuff. Then, when you've got a grasp on the basics and you start moving into like advanced stuff -- find yourself a sushi place with real actual japanese people in it, and go there. I don't know what it is -- Japanese people, by and large, [i]love you[/i] when you try to learn their language. Like I mean..... speak German to a German, they'll be happy I guess, speak French to a French, you're wasting your time, speak Spanish to a native speaker of choice, anything can happen, Chinese, whatever.... but JAPANESE fucking LOVE YOU. They'll help you out. So go out for Sushi like once a week (or every other, or whatever) and practice having regular conversations. You can get good pretty quick.

You'll hear people say anime doesn't help. Not true. You'll learn from context when it's appropriate to say "Yokai" vs. "Hai" vs. "Wakatta" vs. "Yosh" vs. whatever. You'll pick up some cool phrases. And of course varying levels of cultural exposure (Samurai stuff is pointlessly irrelevant, but did you know female storekeepers shriek at you when you come in? That's something you might've learned from television)

Anyway the important thing is always exposure. Depending on where you live, exposure to Japanese can be pretty hard to come by, but find some and practice. You'll catch on. Steep learning curve but it's fun.