In THEORY, I should be able to edit the move names to english ones, but I don't have a tool that will work on a japanese rom. Everything I've tried so far doesn't play nice with it. Or, well, I'm ASSUMING its a language problem. It may very well not be, I've never done this before. @_@
EDIT: I tried one of the tools on an unpatched japanese rom, and same result. So I am assuming its not an issue with the patching.
Most of the tools here are for English roms, and the offsets are most likely different. I don't know where the offset for the moves names are stored (they are independent of the actual move data), but it should be simple enough to convert a move's japanese name into hex, and search for it with a hex editor. You could then change the name accordingly, through hex editing.
It requires a fair amount of editing the hex structure of the rom...There's a "tutorial" floating around in the research and development thread, I think. I attempted to put it in my rom hack, but it just messed up everything. Feel free to try it, if you want.