Ethical note : Level-5 has never released this game in the West. By downloading the patch, you are not costing them a sale (because a sale was never possible). However, supporting the series by buying official merchandise or the 3DS titles is always encouraged.
For many years, the most accessible "patch" was actually a texture pack for the Dolphin Emulator . Projects like AkiraJkr's Translation Project English Patch Inazuma Eleven Go Strikers 2013