Since there was never a PSP version of this game, these "ISO" files are often just renamed APKs or, worse, malware designed to look like a game.
Fake APK files may request invasive device permissions (access to contacts, SMS, storage) to steal personal data. Since there was never a PSP version of
Bad Guys at School Mobile: Download and PPSSPP Emulator Guide Use official sources and enjoy emulation responsibly
If a website promises a free, rare PSP game with an “APK+OBB” for PPSSPP, it’s almost certainly a trap. Use official sources and enjoy emulation responsibly. it’s almost certainly a trap.
You will need to find the game file (often listed as Bully: Scholarship Edition for PSP).
If you persist with the PPSSPP route, stick to trusted communities (Reddit’s r/Roms or r/EmulationOnAndroid) for advice—
Never sideload an APK from a ROM site.