I don't really agree with u but it's your choice :p
Anyway.. I don't have Shikigami No Shiro1 so I gave a look at shikigami no shiro 2 PC and PS2.
I presume that they present some similarity.
Purely by looking at the tree in the game directory, there are not too many places where to hide the text:
-the exe (in both versions and i belive that i have seen some English and Japanese text on it and somewhere it say something about "huffman" so the LZSS compression u was talking about is probable)
-the 2 bin in the directory media (not think so)
-any of the bin or har files in the directory cdimg
The PC and PS2 version they have the same .har files on it and even some named the same name so i belive that if u can crack that file, u probably can translate both versions.
Har is looking like an archive file with 1 or many files inside of it:
4bytes Magic word "HGAR"
2bytes ???? x0700
2bytes number of files in the archive
4bytes start offset in this file of the first file in the archive
4bytes start offset in this file of the second file in the archive
4bytes end offset in this file of the last file in the archive
4+4bytes for each file in the archive (many xFF00FF00) maybe a sound call?? (xFF00=no sound)
File listing (the following part is not present in all files and it's not precise)
2bytes Consecutive numeration of the files (starting with x00)
(in cs_title.har, there are 2 times a number 3 referring to a copy_taito.hpt, i belive a Taito logo that is not present in the PC version)
3bytes Null x0000
xbytes Name of the first file in the archive
2byte Null x0000
2bytes Consecutive numeration of the files (last file)
2bytes Null x0000
xbytes Name of the first file in the archive (last file)
4byte Null x0000
Data start (normally all files start with the name of the file and the offset point to the first letter of the name)
I checked the single file only with a bmp, i saw only later that inside the exe there is the word "JPEG" so maybe should check with a Jpeg header.
If u have a working LZSS de/compressor, could u pass it to me??
By looking at the file list on the har files, i noted many files named .mes ..sound interesting and in the file system.har there are many files with "font" in it.
By the way, here u have some japanese text extracted from PS2 executable (above) and the PC executable (below):
I hope i could help u a bit.
Work is calling me now