The 2002 GameCube game was fully localized. The 2023 arcade ROM is 95% Japanese. Fan translation patches exist, but they break the game’s anti-tamper checks. You will often see "English Patched Ultimate Muscle ROM" in search results—proceed with caution, as these are the most common vectors for malware.
However, as of my current knowledge base. It’s possible you’ve encountered: Ultimate Muscle Legends Vs. New Generation ROM ...