More than 90% of learning a foreign language is rote learning, especially vocabulary (and for Japanese, Kanji). So make it a habit to practice daily, just a little bit is enough. Apps like Anki (http://ankisrs.net/) help a lot. The rest is grammar, and getting your brain "re-wired" to think in the patterns of a foreign language. This takes time, and you usually can't rush it, and it takes longer if it's your first foreign language. It also works differently for different people; some people read a lot, some have to speak a lot, etc. Find out what works best for you. For grammar, I recommend http://www.guidetojapanese.org/learn/grammar. Read it from beginning to end (over a longer time span), and you should be fine. It's normal that listening starts out slowly; it was the same for me. You first start to recognize single words (blabla wakarimasu blabla), then groups of words. Also, at first it's much to fast, you can process a few words and then you get lost. That happens to everyone learning a foreign language. Just keep doing it; maybe listen several times, and look at a transcript. You will also have trouble to say things, because you don't know the right words or sentence patterns to use yet. The trick is to express yourself with what you have, so try to hint at what you mean, describe it etc. It will sound childish, but you often can communicate successfully this way. Polyglots use this approach excessively.

In my opinion, it's better to start from the basic grammar remembering the Japanese words little by little. There are a lot of web pages which teach Japanese and many learners of the Japanese language here know the good ways to learn Japanese. Please ask them, for example, "how do you learn Japanese?", "which are the good web page to learn Japanese?" Good luck!

Efficiency...it is difficult... I think you talk with native speaker of Japanese a lot. I also would like to know how to leaning English efficiency!!