Aaaand now that I’ve written this in German, I’m too lazy to write a translated version.
It’s much more convenient to just write things in one language without having to translate, so I’m just going to paraphrase what I’ve written into a shortened Version:
I’ve learned a lot of Englisch via exposure to written texts, videos, TV shows, movies etc., but I think you’re wasting time if you’re trying to learn a language only by watching TV shows/ movies.
It’s much more efficient to study conventionally (i.e. studying vocab and grammar) at first, until you can understand >60 % of what is being said. If you can already understand most of what is being said it’s much easier to pick up new vocabulary purely from context.
Oh and merely watching won’t teach you how to write most words (this applies to English as much as it does to Japanese).
Watching anime will, at most, improve your listening comprehension and maybe allow you get a feel for the language IF you already know a bit of vocab and grammar.
So yeah, if you’re trying to learn Japanese only by watching anime you’re not only wasting your lifetime but you will also stay illiterate forever. If a single hour of studying is worth 10 hours of watching anime in terms of the amount of knowledge you get from it, which one is the one you should be dong
So I’d say study grammar, study Kanji, go read shit and get exposure to the written language (and learn how to pronounce the syllables correctly) and at a certain point it’s likely that your learning will become self-sufficient and you won’t really need to actively study much. I’ve actually stopped actively learning English vocab because of this; there’s only ~ 1 word out of every 10000 words I read that I don’t know.