Darn, I was really hoping I wouldn't have to deal with spoiling content. I will look into this immediately.
The garbage text is normal as it's supposed to be decoded by the Chinese locale, but it's being decoded in UTF-8. This is done simply to prevent certain locales from crashing. A translation patch should resolve the problem as long as it's compatible with my patch.
I am very sorry with the inadequate amount of testing I am doing. I am prioritizing this project over playing the game myself, so I don't test the game fully as I've only gotten to Stage 4.
I will update the OP to explain that there are still issues.
I'd also like to personally apologize if you were doing a legitimate run and this happened. I was really hoping something like that would never happen; it may as well be my worst nightmare is respect to this project.
EDIT: Okay, this is actually very bad. This is so bad, I'm pulling the download off the original post. Encoding.Default is actually used in many places.This means a lot of data get decoded differently in several different aspects of the game. THE PLAYER SCORES ARE SAVED THIS WAY, which means that any .dat files people share MIGHT NOT BE COMPATIBLE ACROSS LOCALES. I will put the download back once I can eliminate all of these issues, because there's nothing worse than segregating a game community.
EDIT 2: Maybe not as bad as I initially thought. Player data seems to load fine no matter what the locale is due to the characters used for it being near universal. I am however staying wary of it.
EDIT 3: I am NOT playing through the whole game just to debug a crash. Let me take a shortcut and give myself a boost.
...Even with the boost, I'm absolute trash and beating her is difficult.
FINAL EDIT: After struggling with beating this woman (Don't take that out of context!) for at least an hour, I believe I may have fixed the issue. I made seemingly appropriate changes to the several locations where the default encoding was used, and I do not receive a crash when the ending loads on either English or Japanese locales. Before you ask, no, I am not debugging other locales right now. I will debug a locale once someone reports there being an issue with it, as YuyuKoishi and RegalStar did.
Before I distribute this new release candidate, I need to do some final checks, but I will need time to do that.