Help with extracting character CGs from visual novel.

I've gotten into extracting data from visual novels, slowly learning to use various programs as I go along, but I've ran into some problems with one. When I use GARbro to try and extract CGs from Gachinko! Bitch Club, I only get event, background, and opening CGs for the game, but no character CGs. When I use other programs like ExtractData or Multiextractor I only get .ogg files (which also don't show up when I use GARbro). Also all of the CGs that I can extract are labeled "back" followed by four numbers which are 0000-0765, with back0765 not even being a CG but just a file with .file extension.

Has anyone else who's tried to extract data from this game ran into this same problem or was able to figure out the solution to this problem?