As it turns out, this artist has quite the cinematic universe (mostly of videos) these doujins take place in. In a couple of them (1, 2; no translation), Flandre puts on an adaptation of the Phantom of the Opera musical. She ends up casting the following:
Phantom (basement-dwelling weirdo) = Flandre Christine (female lead) = Sakuya Raoul (Christine's love interest) = Meiling Meg (Christine's friend and colleague) = Patchouli Madame Giry (ballet mistress) = Remilia Carlotta (ousted arrogant primadonna) = Tenshi Piangi (Carlotta's opposite actor and, in Flandre's version, husband) = Iku Firmin (opera manager #1) = Suwako André (opera manager #2) = Kanako
We've been doing all the make-up and costume changes for "Theatre Troupe Vampitheatre" just behind the curtains, but I think having a proper dressing room wouldn't hurt...
Patchouli
Hmm, indeed...
Did you get permission from Remilia-sama?
Of course I did!
Very well. I'll have the space ready by tomorrow evening.
You can handle the furnishing yourself, hmm?
THANK YOU—!!
Good night, Sakuya—!
...Look at the time. I really should go to bed as well.