There is a tool called translator ++ that seems to be able to do a pretty good job at it. For changing the font, I have an idea for a terrible solution, which might or might not work, but I'll mess around and see if I can get something working. If I can get it to work, there might be a solution! Although it might only support hiragana, simply because there are too many kanji to fit in. But I'll see what I can do!
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I actually did some research and also found translator++ which seems to work pretty well. I was able to extract all the game’s text and experimented by translating a bit if dialogue to Japanese. As expected, when I exported it to the game and tested it, the text just became blank. So yeah, the font is gonna have to change. I’ll be looking forward to hearing your solution if you get it to work.