DJMAX Online .pak files

[Extreme_Z7]

DJMAX Online is an old freeware MMO rhythm game that was active from 2004-2008 in Japan, Korea, and China.

I have a copy of the game and I want to extract some of the system files. I mainly want the UI images.

There are 22 System .pak files in total but I've uploaded the first 4 system files to the links below:
https://mega.nz/#!k5dnQJqQ!ZrS74QwxSb44 ... 0eCvwVElLw
https://mega.nz/#!l8kg2QLZ!MAVTpatkuUIr ... 6lfkeJjhUE
https://mega.nz/#!5slThCgY!qcjtjOINR4hf ... xrEKDnamSI
https://mega.nz/#!Qg0ViBxQ!szAwEquVQpML ... TlfTv2QRiU

I really have no clue on how to begin decrypting compressed game files nor do I know of the structure of these specific game files. Just hoping someone here knows how to make a BMS script for them.

[aluigi]

Since nobody else replied, well the XIP2 (your samples) and XIP3 archives have been already discussed years ago on Xentax without success:
https://forum.xentax.com/viewtopic.php?f=10&t=10437
I agree about the "unknown" compression (it's not lzo1x) and there is probably also some obfuscation in use, maybe just on the filenames as Ekey stated.
In short, there is no solution but everybody is welcome to contribute.