My CPK file isn't opening...

[Angelc0re1204]

I'm attempting (trying, failing, failing miserably) to make an English patch for a game that follows the general pattern of otomate/criware/rejet/ideafactory files.That being you have a GAME.cpk, SOUND.cpk, MOVIE.cpk, and SYSTEM.cpk in your data folder. there is also an eboot.bin file that I've already identified has having no discernable text that would be a line someone says in game. I've tried every tool out there. Quickbms, cripak tools, cripak GUI, VGM Toolbox, you name it with a link, I've probably already tried it. I have tried to use a hex editor, however the data isn't human readable, and I can't switch the hexidecimals/output to Japanese and try to discern something that way. I'm at a loss. I also tried other games with the same otome structure, and those don't work either.
they always say that the CPK isn't valid, or that it's unreadable.