Here is the harsh reality. While emulators themselves are legal (they are simply software), downloading a copyrighted ROM from a website is in almost every jurisdiction, including the US, EU, and Japan.
Naruto Shippuden: Ultimate Ninja Storm 4 is a fighting game developed by CyberConnect2, the same studio behind the previous games in the series. The game features a vast array of characters from the Naruto universe, including fan-favorite ninjas like Naruto Uzumaki, Sasuke Uchiha, and Sakura Haruno. The gameplay mechanics have been refined, offering a more fluid and responsive combat experience. naruto shippuden ultimate ninja storm 4 rom nintendo switch