[marsavar]

People are reacting quite strongly to this answer, but it is unfortunately correct. OP has essentially created an application for memorising vocabulary, which is... fine, and it's an achievement to be celebrated.

But no amount of flashcards will make you a competent language speaker. There is no substitute for immersion.

What made it really click for me for me was reading. Lots and lots of it. My suggestion is to start with short, easy stuff (stories for kids) and then move on to progressively harder material (short newspaper articles, essays).

I passed JLPT N1 back in 2013, and preparing for the test was just an exercise in memorising vocabulary and grammar patterns. What really made the language click for me was reading novels in Japanese. That alone helped me more than any amount of Anki-style JLPT prep material ever did.

Vocabulary is important, but it's much, much easier to absorb and retain if you learn it in context.

[tillcarlos]

Do you know of a tool that can generate texts to read based on exactly your level?

I think that was Krashen’s input hypothesis. If I read a text in Vietnamese with more than one unknown word, it’s too much. Exactly one would do it.

Haven’t seen a tool doing that.

[wren6991]

It's a numbers game. Sentence complexity within a given novel follows a distribution, and if you keep reading then you'll keep getting some input that is at exactly the right level for you to grow. It's normal to stumble on the exposition at the start of a chapter and then breeze through the dialogue.

I did find it helpful early on to go through web novels with a low 95% coverage vocabulary count, like the Narou stories indexed here: http://wiki.wareya.moe/Narou

Natively is a great resource too. It does Elo-style ranking of novel difficulty: https://learnnatively.com/browse/jpn/?language=jpn&lvl=

I highly recommend real stories over generated text and synthetic exercises, because the key to success is staying engaged long term. Stories are just more fun. Also get yourself a reading setup that minimises the pain of dictionary lookups, because there are going to be a lot of them. ttsu reader + yomitan is excellent.

[tkgally]

That matches my experience, too. I passed JLPT N1—then called 1-kyū—back in 1985 (!).

I did spend a lot of time memorizing vocabulary with flashcards, but I spent even more time on extensive reading—novels, newspapers, magazines, anything I was interested in, even if at first I understood little. The repeated exposure to vocabulary in real-world contexts really made a difference.