Since the later bosses seem to have a way lower drop chance for non-event girls (from what i've experienced so far) I was wondering if the drop chance for event girls is structured in the same way.

I'm not quite sure which boss I should farm, so here are my questions:

1. Are drop chances for non-event girls and event girls the same for a specific boss?

2. Is there some kind of shared "bad luck protection" between bosses, non-event girls and event girls or is it independent? Or is there no such thing and players can theoretically end up trying a million times without a getting a girl?

3. Do earlier bosses have a better drop chance for event girls?