Well, let me correct myself a little. I don't have technical expertise in this field. I have some coding (really beginner level) skills and can manage some issues... not complicated ones thou. But this translation going rather smoothly, maybe I just got lucky with my primary language (I'll explain further) and existing tools.
First of all, I just asked DeepSeek about what I need to translate this particular game and what resources I can read. It correctly identified QLIE, and gave me possible tools to work with game files. Also, linked me this article, on russian (my primary language) about QLIE, that helped. It explained a little about tools for working with the engine and some innerwokings of it. A couple days of trying things, reading forums, github issues and asking DeepSeek what to do, I managed to extract, change and pack scenario text back into the game. Tool for packing is arc_conv by w8m, which has decent documentation, but again, on russian. So, game files shenanigans are over and I could proceed with translation.
I have a friend who translating korean web novels on russian using Gemini. He gave me his promt and I modified it for jap-eng translation of visual novel. Then goes a couple of days of trying to befriend Gemini and script files, to get results needed minimal editing, by this point promt became 1,5 times larger. Then I added some setting and characters descriptions into the promt, because translation was inconsistent without it. It still has some junk, but not as much. Promt was corrected throughout work process and I still think it's incomplete, tbh. I didn't use any API, because aistudio can work with a lot (~1m) of tokens in it's web interface. So it was just tedious process of copying file content to a txt changing ShiftJIS Encoding into UTF8, because LLM don't understand ShiftJIS, and copying the result back. It was 280 files, the work took me about a week.
After that I'm just reading and correcting minor neuro junk, like untraslated parts, names or corrupted script (not common ocurance, but it happens).
I think this process could be a lot easier for someone who knows what they're doing, but I'm still pleased with the result.
I hope I satisfied your interest, if you have any more questions - ask, I will be happy to answer.
I get what you're saying, but result are surprisingly decent, in my opinion. Much more readable and consistent than sugoivisualnovel translation for example. Gemini can get context of the whole scene and can use characters descriptions from promt. Also if there is some questionable moment, again, you can correct it in promt. Another lucky moment for me, Google released latest version of Gemini just a couple days before I started translating, I believe it had positive impact on the result.
Anyway, It will be really cool for someone give it a read and share their thoughts about this translation.