The Japanese release features unique content and censorship not found in the original Western versions:
Most "Japan ISO" downloads online are actually: Download Grand Theft Auto - Vice City -Japan- -...
Interestingly, the fire sprites for explosions are significantly larger in the Japanese release. Capcom Publishing: The Japanese release features unique content and censorship
The original Japanese version is primarily available on older physical media. Most modern digital storefronts now only offer The Definitive Edition Download Grand Theft Auto - Vice City -Japan- -...