Community patches often focus on translating the menus, move lists, and key UI elements to make the game playable for non-Japanese speakers. Full story translations for the PSP-exclusive text are rarer and often distributed as .xdelta or .ppf files.
Because it is a Japanese import, all menus, story text, and system voices are in Japanese by default. English Patch and ISO Details
where players compare the different "Extend" versions across platforms. translated menu guides
Enhancing the PSP Experience: A Comprehensive Guide to BlazBlue: Continuum Shift Extend ISO English Patch