Hmm, I actually really like WaniKani’s approach to breaking down Japanese.
For those unfamiliar with moon runes, most of the words are written using characters inherited from Chinese. These are the ones that can get real complex and have full, valid meanings even when not combined with other characters. These aren’t just chicken scratch though, they’re actually made up of small (and sometimes nearly unrecognizable) components, so-called radicals.
WaniKani incorporates these components into their lessons, starting out by making you remember a seemingly arbitrary name for these. Once you’ve proven they’re stuck in your head properly, it moves on to teaching you some characters that are made up of those radicals, using their names as part of a mnemonic for the meaning and/or reading of the character. And once you’ve learned those, it teaches you the full vocabulary words that use those characters.
Turns out that when you know one part, it’s pretty easy to learn all the things that make use of that part.