Because Koei Tecmo did not localize the PSP version, the only available text and audio are in Japanese.
The English translation for (the PSP version of Warriors Orochi 3 ) is largely a community-driven effort, as the game never received an official English release on this handheld platform. Current State of the English Patch warriors orochi 3 psp english patch upd
For those looking for a complete, official English experience, the is available on Steam and includes all content and previous DLC. Because Koei Tecmo did not localize the PSP