I try to patch it but it's still in japanese (clearly, I'm doing it wrong somehow), so some help would be appreciated^^.
The main menu of the patched version is still in Japanese due to technical difficulties, but the fullscreen and quit buttons at the top of the window should be in English. Could you double check? But I'll take some screenshots or video and put together a guide later today.
Everything's in japanese for me.^^ If you do I'll be very grateful <3
When you run xdeltaUI and select the files, it should look something like this: https://imgur.com/a/Xq8HQl6
(With C:\path-to replaced with the actual file locations on your computer.)
And make sure the output file is in the same folder as live.dll (packaged with the original game & required to run it).
Then click Patch. "File patched successfully" should pop up when it's done. And run MyGamePatched.exe (or whatever you called it).
If your issue is before that point (running xdeltaUI, etc.) let me know.