Hurray! I finally got Miss Spook, so I can move on to Edwarda.

As a suggestion to the developers: each boss already has its own quest-item for the storyline. Maybe it can be set to keep dropping that quest-item after the storyline is cleared for that boss, and use it as a currency to free the girls from that boss? Like, collect 500 or 1,000 ripped masks from Donatien to free a random one of his girls, excluding event girls (optionally, make event girls cost double the amount to set them free, which is fair, since those girls already have a higher drop rate, and the point is to get them to drop, not buy them free, while leaving the option for the really dedicated players who lack any luck to still aquire them in that manner).