This is very strange - I have found the opposite lately. MIT stickers over MIJ ones.
Actually I think they have started fixing the problem by reversing it.
If you do spot a spindle with MIJ originally on the spindle's cover (next to the UPC) then they are likely MAXELL,s own brand with media code MAXEL002, and in my opinion they are poor (extremely high PIF total count). I was once a big fan of Maxell media, but since end 2004 I have been avoiding it like plague, they have gone down in quality, both the maxell's own brand and their riteks.
Now Maxell has introduced a lineo f Maxell PLUS series, professional grade and claimed to be better than Taiyo Yuden - I have not tested those yet.