Thanks for your replies. By the way, did you find any readable texts in the editor? 'Cause I didn't see any in-game dialogues; only rubbish (could it be that the fonts are compressed???).
On the other hand, I've said that I didn't find the あいうえお before (and no it's not because I overlooked it--it's a different PC). I used Win7 at home, and WinXP at our Engineering lab (...). Everything's the same for both cases, except I can't view what I could in the WinXP PC.
So, at home I had to use a different editor (MadEdit--is there a way to make it use a specific table instead of just changing the encoding?) and it worked out okay, except that I still couldn't find any dialogues (I tested Black/Matrix 00 and at least I found the data for the items, skills, accessories etc as well as the game's option menu. But no dialogues--wait, there's one (a prologue): 翼はおどる...裏切りの刃...blabla.
What crucial thing I've missed out? Maybe I should try translating the ones that have been translated to understand further...