You get this a lot in works. Even simple stuff like One Piece. All the sea names are English. Like East Blue. But they’ll be written in normal Japanese with kanji, 東の海, while the furigana besides it is イーストブルー.
Dragon Ball, Super Saiyan’s furigana is obviously スーパーサイヤじん. But the actual way it’s written is 超サイヤ人.
A lot of it is for flavor or extra context. It’s one extra layer of expression they get to use in their media. Most of this goes fully missing in translations, where they’ll just choose one and ignore the other. Since we don’t have this in English. (Almost everything interesting and fun about manga gets lost in English localization, fan and official, but that’s a whole other can of worms.)
may I ask how you are able to reach this level? I can read many kanjis but speak like a child…
Get audible and read any book while listening along to the audiobook. Set the audiobook speed low enough you can somewhat follow along.
But you’ll probably have to do a certain amount of studying kanji outside of reading. I recommend wanikani lol
As it sounds like your vocab knowledge is pretty extensive already, I could imagine a purely kanji focused method would work well for you. It’s much easier to remember meaning and reading of a kanji if you know a word that uses it. I‘m personally using a modified version of this deck for example.
Actually, thinking about it, why not try a kanji book made for Japanese children? Since your strengths are closer to a native speaker child than the average adult foreign language learner.
