The PSO2 Tweaker is basically a replacement for the normal PSO2 Launcher, used to update and launch the original Japanese version of the game. The Tweaker adds several options to the game, such as the option to remove the censor file, automatically download and install new English patches as they are updated, and much more! You can download it by clicking this link or the picture below.
The tweaker requires at least the .NET Framework 4 to run in Windows. You can grab the install for that here.