Looking at the mood of the thread, I'm not quite sure if I should do this, but I feel like there's some people it could help so here goes.
I don't think the method of learn through use of games/anime/manga/etc deserves the shunning it getting, because if you go about it properly, these are very viable methods of learning to read and listen to Japanese, which I think is the goal of a lot of people that are trying to learn the language.
Sure, doing things like watching English subbed anime forever without doing anything else will probably be an ineffective use of time, but that doesn't mean these methods are useless.
Through studying some basic grammar first and making use of tools that enable you to look up words quickly you can simply learn as you go along reading the things you've wanted to. It will be quite the struggle at the start, but if you're reading something you've been really hyped for it turns into something manageable.
And I think it's safe to say it's a bit more fun than grinding kanji like crazy for months.
One of the things I'd recommend is to learn vocab directly instead of kanji, as by doing that you'll be "learning" kanji at the same time with little extra effort, thanks to pattern recognition. Simply recognizing the same kanji in multiple different words will eventually make you build a mental list of the readings it can have and a general sense of the type of meanings the words that contain the kanji have (if applicable). Which makes remembering new words easier as you go along, since you can often make a good educated guess at a new word if it contains kanji you've encountered before, so more effort can be spent on memorizing the meaning of a word.
Meanwhile, if you focus on memorizing individual kanji instead, even if you learn a bunch of words that go with then, you'll still have many other words you'll need to learn later on anyway, as the ratio of words:kanji is very shifted towards the former.
Learning words also has the advantage of being able to learn them as you read. Each time you look up a word, you'll remember it a bit better than the last time, until you don't forget it anymore. the non-basic grammar can be learnt in the same way. It might be hard to notice yourself making process this way and it will be very tough in the beginning, but trust me you will.
Furthermore, I don't recommend using the JLPT tests your main goal, to the point where your studying is spearheaded at mainly just the grammar points and the vocab tested in them. Unless the main reason you're learning the language is to take the JLPT, it would be a good idea to widen your focus a bit more to learning the words you'll be needing to read. The JLPT is a test that tests your reading/listening skills, so even if you just study to be able to read well in general, you shouldn't have much of a problem with passing even the N1.
Once you've gotten the foot in the door and can read well, learning to speak and and write well as well shouldn't be much of a problem, just remember that people in reality don't speak the same way as fictional characters do and you should be fine.
In the 1.5+ years I've been studying Japanese so far, I've mainly been enjoying myself through playing the
various stuff I've really been wanting play to but couldn't.
Learning a language, especially one like Japanese, is often thought of to be this incredible impossible hard thing which you'll need to suffer through and endlessly grind through in order to get any good at, but it really doesn't have to be this way. Seeing people being so dismissive of methods to actually making things enjoyable saddens me a lot.
In any case, I helped on writing a guide that contains general advice and how to use the tools that will make your life easier:
https://docs.google.com/document/d/15uvv72eVFBtcOlfHaHUfT_HhZsgWxd7VjT9u-zVSwdw/edit
Please take a look if you're interested, hopefully it will be of help.
Now that I have an account, I'll probably be checking out this thread more often and answering questions if people need help.