help with decrypting

[aister]

I don't know if this is the correct place, but I don't know where else so...

I'm currently translating a Japanese game into English, and while trying to extract script files, I came across an encrypted file.

Here is a sample file: https://github.com/aister/FGO-Story/blo ... 040110.txt

Also, I got the decrypted for the sample file, it was taken before the game encrypt the scripts. However, there were no decrypted files for the files I need. I think this might be helpful in knowing how to decrypt the file.

Decrypted file: https://github.com/aister/FGO-Story/blo ... ecrypt.txt

I don't know if this is simple or not, because frankly I don't even know where to start, I'm all new to all this encryption thing so... if anyone can help me with anything, it would be very appreciated.