You may still get a game crash. Don't worry, try to ignore it, everything is OK. If you still can't play, switch it to English, and switch back after passing the crash part.

Download:
How to install
Download the zip file and unzip it. Put the file in Milfy Day/game, overwrite the original file.
If it's a Mac, put the unzipped file in here: MilfyDay.app/Contents/Resources/autorun/game
How to use
When you put the file in the right place, you will see the language button in the upper right corner of the game menu, click it to switch your language.

