So... US/JP PSP via Kai?

[Yusaku_Kudou]

Or US-US and JP-JP only? I have had the JP version since last year and a friend is wanting to buy the English version.

[Iriscal]

Yup. It's version-incompatible. You'll have to get your own US copy of PSP and play it instead. You wouldn't normally be able to transfer the save data, but I have a tutorial about it at http://pso-world.com/forums/showthread.php?t=159721

I'll be doing all the conversion requests over the weekend, so drop me your Japanese version savefile in that thread if you don't have custom firmware.

[Yusaku_Kudou]

No, it's okay... I prefer playing it in Japanese anyway, but thanks.