Ubu writes that, contrary to Aroduc's assertion (which Ubu forgot to link, tsk tsk), Sekirei ep.12 is "not introducing new characters at the end; all of those have been shown before, most in that episode." While technically true, Aroduc's point still stands: creators were gunning for a sequel.

Since we're on topic, Aroduc's "prepare to find out... NEVER" was erroneous as well, strictly speaking, because we've been shown in ep.12 who the characters of the series preview were (and Kurasuba was well known to us well before ep.12). But then again, we weren't shown just what exactly happened. It's the same kind of mystery that transpired in Naruto... including the special baby who becomes a main character.