If you want to learn to speak and write Japanese, then that's more difficult, and probably impossible, to accomplish through self-learning. You won't be able to reproduce intonation appropriately without practice speaking to someone who is already fluent in the language. Nor will you be able to pick up the social cues that tell you when to speak in formal, humble, casual, or informal register.
However, I don't recommend trying to learn Japanese in Japan until you are up to an intermediate proficiency at least. There are many language schools for foreigners in Japan, but frankly it's expensive and you won't get that much out of a beginner course in Japan that you won't get from a beginner course or by self-learning at home.
So my suggestion would be to take local/online courses or self-learn until you are roughly intermediate, then take language courses in Japan if you want to try to reach that upper Advanced/Fluent level.
Alternate ideas..
I want to be able to:
* Ask for directions in Japanese
* Tell a joke in Japanese
* Write a letter congratulating someone on their new job
* Order food in a Japanese restaurant
* Hold a conversation in Japanese about topic X - (My life, my hobbies, the weather, my recent vacation, etc)
* Watch a Japanese movie w/o subtitles
etc..Having a specific real-world goal like that makes it WAY easier than dealing with word lists and grammar rules, and trying to 'synthesize an sentence based on rules in your head'. I found the structured book based approach to be very boring. We all learn differently of course, so you may have success doing it either way.
Good luck!
https://en.m.wikipedia.org/wiki/Common_European_Framework_of...
For A1 or A2, you can easily be self-taught. Lots of materials work (see below). You will need to refine your skills once you are in a native speaking environment, but you should easily be able to do so. Many Americans consider this “fluent”, but I would call it more like tourist-level proficiency — working in a Japanese-speaking organization would be impossible.
For B1 or B2, I suppose you can be self-taught to this level, but perhaps only with receptive skills like reading and/or listening. These are the levels where you need to feel comfortable with authentic texts. For productive skills, it will be tough to reach this level without being in Japan — it’s just awkward to try to create authentic daily situations with a teacher in a comprehensive way (it can be done and is done, but it is expensive and time consuming).
For C1 or C2, you need to be in country. In fact, you need to be living in the language. Most/all media, conversations, etc. will need to be in Japanese for a while (1-2 years for C2 would be doable if you start with a solid B2 baseline) before you can reach and sustain at this level.
Recommended materials:
Japan Times materials — they are pretty much all good. Good for A1 to B2.
Japanese Language Proficiency Test (JLPT) 日本語能力試験 — This test has 5 levels, and they release old tests. The tests themselves are designed very well. Look through one to get a feel for what you need to know. When you think you’re at level, take the old test. After your done, break down every question and figure out what the right answer is, why it’s right, and why the others are wrong, and why those wrong answers are good distractors (some distractors are aimed at non-English speakers, so don’t over think this). Rinse and repeat. For me personally, this was a great way to find gaps in my knowledge.
Jorden books (Beginning Japanese and Intermediate Japanese). This books are ancient with some outdated vocabulary, use a suspect teaching method (it sort of works, kinda), but the technical lingustic explanations are the best I’ve seen. As a simple example, I’ve never seen better explanations of when to use the particles は and が for beginners than in that book (a better one may exist, I just haven’t seen it). When I was learning, this helped me crush the first two levels of the JLPT (Japan Times stuff better for higher levels), and I helped friends do the same when other textbooks and teachers were lacking.
Duolingo — I just love this software for a basic intro to the language. I’m not sure what level it gets a learner to — maybe A1? That said, it’s a low friction way to start.
This is an area I know a lot about, so please feel free to ask follow up questions.