"PS3 Executable Not Found In Selected Folder"

I ripped my copy of Hakuoki using IsoBuster, put the .iso into "dev_hdd0/game/BLUS31187" and get this error when I select that folder to boot game. I'm guessing that just ripping the .iso isn't enough and I need to do something else. What am I missing? ^_^;;

What files do you have inside the BLUS31187 folder?
Could you run "tree BLUS31187 > file.txt" (on the game directory, right click with shift pressed down and click open a new command window here) and post the file here?