It's hard to guess what that means without seeing how the game uses that data. I don't think things are compressed or encrypted here, as we can see clear text. You should try using PPSSPP's debugger.
Here's an example of what you can try:
Use PPSSPP to go to an untranslated scene.
Open the memory viewer, press the right mouse button and take a memory dump.
Open the dump in an hex editor that supports utf-8 or shift-jis, I don't know what the game uses... You may know better than me.
I personally use the 5.0 beta from http://www.hexedit.com/downloads.aspx
. You can change the character set in View, Character Set.
Hopefully you'll find the untranslated text. If you found it in the dump at position, say, 0x123, it is actually on 0x08800123 on the PSP. The 0x08800000 region is where the user available RAM is located on the PSP.
You should probably search for the hex code sequence equivalent to this text in all your files... If you have a lot of files, I'd suggest merging them on a single file so it is easier to search. I use 7zip's tar to do this. If you can't find it in any files, then it is probably compressed/encrypted/encoded in another character set... In that case we need to use PPSSPP to see where did that text come from.
Open a game save just before that untranslated scene. Make sure the text isn't in RAM at this point (open the memory viewer with Ctrl+M and go the the position the text is located to check that. Remember to add 0x08800000 to the position you found the text).
I'd open the PPSSPP debugger(Ctrl+D), set a write breakpoint to the position you found the text in your memory dump (again, remember to add 0x08800000) That way the emulation will stop when that address gets written. Now proceed to the scene where the text is located. Hopefully the emulation will stop and you'll be able to see the MIPS instructions responsible to getting the text there.
I hope this is enough for you to get started... I know it seems complicated, but you'll get the hang of it.
If you can't find the text in RAM in the first place, you'll have to open the PPSSPP graphics debugger, find how the text is getting displayed on the screen, get the offset to the texture where the text is written, and setting a write memory breakpoint to that texture to so you can make the emulation stop when the game writing those textures.
Also, did you check the main executable for text? On PPSSPP go to Tools, Developer Tools, Dump Decrypted Eboot.bin on game boot.
Now open the game, and check the "memstick\PSP\SYSTEM\DUMP" folder on your PPSSPP install. You should have a "bin" file with the game code. This is the EBOOT.bin(i.e. the game's main executable) decrypted. There's usually some text there.