It is possible to have English text and graphics with Japanese voices in the demo.
Install either language version. then rename the install dir then run the install file again. it will "uninstall" whatever version you installed first (without removing anything because you renamed the dir

). Then load the install and install the other language. Now, copy the entire contents of of one install folder (ex. copy the entire contents of MEGAMANX8TRIAL to the ROCKMANX8TRIAL folder or vice versa either way doesnt matter) Now, go to whichever folder that contains both versions.
You should have two EXE files, delete one of them (they are both the exact same). Next, there should be two files "ENG_LAN.dat" and "JP_LAN.dat" and a few othes. This controls the voice, whichever is present sets the voice. If both are present it defaults to Japanese. Delete ENG_LAN.dat if you want (it will have japanese voices any way if both are present). Finally, open up the "multingual" folder. There should be two files "japanese.dat" and "english.dat" these control the Text and graphic language. So, delete "japanese.dat". Now this will give you English Text/garphics and japanese Voices

Have fun~
Let's hope the retail ver has dual switchable language install option so we dont have go through this nonsense again.