I noticed that pretty much all of the character tags under radiant_historia are using the names/romanizations from the English version of the game. I'm guilty of using them as well, but I don't really know the Japanese names or how to romanize them to Danbooru standards. post #895399 has all of the major characters and their Japanese names in notes, so if there's anything that needs to be changed there shouldn't be too much searching needed.
Updated by NWF Renim