While standard emulators can run many games using western BIOS files (like the US SCPH-70012 or European SCPH-90004), certain Japanese games utilize unique font rendering libraries and system configurations stored exclusively inside the NTSC-J BIOS. Without the Japanese BIOS, you may encounter: Game freezing at the startup screen. Missing text or corrupted Japanese kanji characters. Audio synchronization issues in Japan-exclusive titles. The Legality of Downloading PS2 BIOS Files