Been working on this for a few months now. You can use a pop-up dictionary directly on the text of any games vn (for the games with only exclusive full screen like tsukihime or fate stay/night there is a magpie compatibility mode).
You can apply furigana directly over the text in game, with either a manual trigger or a continuous setting. It uses mecab by default and it's what I recommend, but if you want disambiguation for things like name there is also a keybinding for ai furiganization.
it uses Gemini to rank definitions by context So when you look up a word like 掛ける that has 15+ meanings, the right one is already on top. I recommend you use gemini2.5 flash lite instead of normal flash or pro, as it's much quicker (1-2 sec) and it's pretty accurate.
It also has support for multiple dictionary profiles when you want to start your monolingual transition, and you can import yomichan format dictionaries.
You can also import cards to anki directly, and there is a setting you can check to not furiganize words already known in anki.
It's free, still in beta. Feedback welcome.
by elwendys