Official game development for the PlayStation Portable (PSP) ended with the original Naruto Shippuden: Ultimate Ninja Impact
While there is no official game titled Naruto Shippuden: Ultimate Ninja Impact 2, the title widely refers to high-quality, fan-made mods of the original 2011 PSP title, Naruto Shippuden: Ultimate Ninja Impact. These mods, often created by developers like Ys, transform the original game into a "sequel" by adding new characters, updated textures, and expanded gameplay mechanics for use on the PPSSPP emulator. What is Ultimate Ninja Impact 2? naruto shippuden ultimate ninja impact 2 ppsspp link
Go to ppsspp.org. Download the latest version (1.18.1 or newer). Available for Windows, Android, iOS (Jailbreak/AltStore), and macOS. Official game development for the PlayStation Portable (PSP)
What you can do legally:
While an official sequel does not exist, the title frequently appears in community searches due to extensive fan-made modifications (mods). Available for Windows
If you are specifically looking for "Impact 2" because you saw YouTubers playing a version with Naruto Storm characters, you are looking for a Modded ISO.