I've been looking into this for quite
a while, unfortunately the JP version is very unmoddable. Every tool would need to be adapted to work with it. Not to mention since there isn't an original JP pc version converting the game to 98 file format isn't likely. You can mod everything in the lgp's (don't touch the flevel though!) so mainly battle, field, and mini game models (maybe audio, I forget). It's definitely worth it if you're a Japanese speaker and want to experience the game with it's original translation.
