Personally, I never understood the whole FlanxKoishi pairing... I mean, it seems like they're only paired together because they're both extra bosses who are the younger sisters of earlier bosses. Then again, my interpretation of the two tends to be quite different from Muffin's interpretations (especially in Koishi's case), so that's probably why...
That
is the only reason they're paired, frankly speaking. Folks find something two characters have in common and instantly you have a pairing on your hands. It's really the one true rule of why folks ship characters and shit. For example; this one works alot like how the whole Wriggle/Yuka pairing thing works out (even though I don't see Fireflies themselves playing much part in the pollination of flowers; Bees, Butterflies and Moths do most of that work).
Matter of fact, I find it odd no one jumps on the Satori/Remilia thing seeing they're both older sisters or something. Ah, I'll never understand you people and your damn Shipping Goggles work...
Anyway, that aside, I have no idea as to who the culprits might be (I have 2 suspects but I doubt that would actually orchestrate this) That panel in the comic before these where Aya and Okuu (don't feel like spelling her real name) were standing around made me think they had somethin to do with it, but...hey, I could be wrong (like always). Also why hasn't Sakuya turned into-
Oh wait, InuSakuya traits kicking in, nevermind...