Here it comes!

...If it's that she has a thing for Mystia, I really hope the response is "well, yeah."

I probably expect Mystia to appear suddenly before incoming confession can be made

Well, given Kyouko is here, she may be confessing that it was at least partially spurned by jealousy directed at Kyouko.

I don't think for a second that Kyouko isn't fully aware of the situation.

I'm quite confident that something's going to interrupt Wriggle before she can finish, just to leave us hanging.

Darpon said:
I'm quite confident that something's going to interrupt Wriggle before she can finish, just to leave us hanging.

I bet it involves Mystia's breasts.

one can only wonder for whose sake did wriggle join Choujuu? mystia's or kyouko's

Touhou_learner said:
one can only wonder for whose sake did wriggle join Choujuu? mystia's or kyouko's

You are forgetting her sheer joy over the tambourine Mystia gave her.