[PC] Little Witch Parfait: Kuroneko Mahouten Monogatari, extracting and repacking archive files

[amarenacherryy]

Hi, I was interested in translating リトルウィッチ パルフェ 黒猫魔法店物語 (Little Witch Parfait: Kuroneko Mahouten Monogatari) and need help in extracting/repacking scipts and assets from .arc files. 
This is a PC port of a PSP game and I have very little knowledge of what should be in those .arc files outside of what I extracted from the PSP game (for example, the PSP game's script is likely contained in one file script.rlpk which is smaller than the PC game's script.arc).

I don't have much knowledge in reverse engineering so I figured it would be better to ask here. 
script.arc (PC) and script.rlpk (PSP) as sample files below. 

script.zip

[Thief1987]

PSP file is very simple in structure and it consists of compiled lua scripts. The second one is most likely encrypted, so without the game debugging hardly anything can be done with it