If I understand correctly - this game has not been translated because the translator can't hook the text. I've sent the inquiry about why it happens to the creator of the widely-used translator program. Hopefully, if I get a response, something can be done about it and we can get an updated Translator that hooks the actual text and this game can be translated!
maybe the problem is the same I have, i tried to machine translate it once. its only a hobby because i wanted to play some games that arent translated. so Iam no expert, but i machinetranslated 4-5 games so far. Iam using the Translator++ tool.
but dieselmine games are a bitch at that point, because they put the dialogs in a seperate scenario folder , t++ translate only the data-folder files in the www-folder (as far as i seeit) there is no option to include the scenario-folder, at least i think so. because of that the menu is english but the dialogs are still japanese, but the problem is, most times the files in the scenario folder are somehow encrypted,
i dont know anything about these SL-files or how to decrypt them, but some of the games like one i own (OF2 in the pictures below) and a project i try to machinetranslate have Text-files instead of SL-files, so i think the main problem to decrypt these SL-files
if my guess is correct at least,
well i dont know what you know , but i hope anything goes well