Gakuen K .pak files help

[Crystal2002]

Hello, I've been trying to crack the .pak files in the PSP (not Vita) version of Gakuen K -Wonderful School Days- (here's a VNDB link of it) and have been getting no luck with it. The .pak files are BGM.pak, Data.pak (Which has bgcmn.dat, thanks HxD, and probably another .dat or two with the character sprites and UI elements), and Voice.pak. I've tried going through Noesis, PakUnpacker, Crage, and Arc Unpacker to try and extract them, but with no luck. Would anyone know/have ideas on how to extract the assets, outside of ripping during gameplay?

Any help would be much appreciated, good luck and thank you!

P.S.- Here's a copy of the BGM.pak and Data.pak