I think Esperknight actually would be a good person to ask about that, over on Romhacking.
He's quite proficient with Sega Saturn hacking, and he has looked at the game before. I think he's been working on the series, like Zero and Oriental blue? I don't remember the specifics, but he and I did chinwag a little about the series at some point since he's tremendously helping me out with a Dreamcast game, Apocalypse IV specifically.
(As far as I'm aware, TMIV, like Princess Crown, was just slapped onto an emulator and thrown out into the world. Think of the Zelda master collection on Gamecube. Hudson did the same thing with the Galaxy Fraulein collection, as well as the Tengai Makyou Collection of Ziria, Manjimaru and Fuun Kabuki Den on PSP). I say crack open the Saturn iso and look through there instead.
Update: The English letters were used here and there throughout the game itself (You have one hella stereotyped character that goes, "WHY? WHAT YOU SAY?" before going right on back into slurred, dialect Japanese.) I don't think they ever really showed interest in bringing it over-- it was a Hudson game, after all.