That tool I wrote, changes the language setting in the kernel. This setting is normally loaded at boot by the OSDSYS program, and any restrictions on the possible choices are enforced in software. So we are free to set it to anything we want. This is a PS2 setting, which will have no effect on PS titles. It is not actually a region setting, but some games take the Japanese language option as an indicator that the PS2 (and hence the user) is from Japan, as only the Japanese console can have the Japanese language option selected. Not all games even check the kernel language option (hence the language selectors). And not all games actually interpret the set language as an indicator of the console's region. In particular, the tool was originally written out of a request to unlock the Japan-only content for the Sonic Gems collection game, which is only normally accessible on the Japanese PS2.