I've studied Japanese a long way back, in high school (3.5 years ago now). I watch anime quite often and pick up a few words - and have started with RTK. I feel that I don't really learn much if I go through a textbook. Nothing ever really seems to stick, except a few vocab words here and there. It feels like I am making little or no progress no matter how hard or long I study.

How do I break the barrier of mediocrity and start becoming fluent?!?

Doing RTK is definitely a huge step towards fluency.
Watching anime is good, but reading is what really makes the difference I think. You can read manga if you don't like books.

Also use Anki for learning vocab, that'll increase the pace a little.
Once you can read kanji (with RTK or RTK Lite) and start learning words (with Anki), you'll increase your reading exposure, and by then, you'll start studying grammar naturally (to understand what you read). The lessons are likely to stick by then, because you will know "personal" concrete exemple (through mining some sentences to Anki of what you read or watch if you have Japanese subs).

The rest is up to you I guess. But keep the fun, that's the most important thing. But just try to do a little bit of learning/studying/anki reviewing every day. Setting up a routine is also very important (ta12121 just said it).

Good luck!

pretty much agree with the above except the necessity of sentence mining.

I think one of the most important steps you can take is simply to start studying by using real materials. RTK is a good first step before starting that. The problem with learning in a schools is most teachers do not understand what knowledge is necessary or useful to teach or what activities students should be directed towards to train and apply their knowledge or gain new knowledge independently. For this reason, depending on the quality of your schooling (I don't know) that 3.5 years may account for very little (I'm assuming you at least learned katakana and hiragana though so be thankful for that). If you didn't learn much at school don't let that discourage you. All too often language education in schools takes the form of mindless sentence memorization, emphasis on production, scripted dialogues and listening to the exact same sentences with a bit of word substitution. The problem with this is, aside from learning some vocab none of it prepares you for the real task of language learning which is interpreting unknown sentences in context.

"Nukemarine's Suggested Guide for Beginners" Topic is probably a good place to start.
http://forum.koohii.com/showthread.php?tid=5110&page=1

Keep in mind that when learning a language, it takes a lot of time. Motivation is obviously a key factor. Sure things like SRS can help optimize your learning, but you still gotta put in the hours. There simply isn't a way around that. Habits take time to form, so make sure language is something you do everyday, that way it's hard to forget about doing it.

Since you have already had some Japanese class, you shouldn't need to worry too much about grammar, you should have a good idea on basic sentence structure with that, so you probably can get to mining sentences even sooner. (Or get to real native material sooner.) In fact it's probably not a bad thing if you have forgotten some of that grammar you learned a while back, as it's a good idea not to be focused on the rules.

Hi Kuto. I'm in the same position as you. Literally, I took 3.5 years of school (actually, in my case, 5 years, but the first 3 years were 'Japanese 1' in middle school stretched out and I finished Japanese 3 before finding this forum).

I found that doing RtK is the biggest thing. It takes away the fear factor of Kanji.

Soon when I finish, I will be able to start reading and watching material. By reading, looking up definitions of words, and perhaps plugging them into your SRS, you can become fluent.